initial commitHEADmaster

1 files changed, 3083 insertions, 0 deletions

diff --git a/src/xfer.c b/src/xfer.c
new file mode 100644
index 0000000..190dfcf
--- /dev/null
+++ b/src/xfer.c
@@ -0,0 +1,3083 @@
+/*
+** Copyright (c) 2007 D. Richard Hipp
+**
+** This program is free software; you can redistribute it and/or
+** modify it under the terms of the Simplified BSD License (also
+** known as the "2-Clause License" or "FreeBSD License".)
+**
+** This program is distributed in the hope that it will be useful,
+** but without any warranty; without even the implied warranty of
+** merchantability or fitness for a particular purpose.
+**
+** Author contact information:
+**   drh@hwaci.com
+**   http://www.hwaci.com/drh/
+**
+*******************************************************************************
+**
+** This file contains code to implement the file transfer protocol.
+*/
+#include "config.h"
+#include "xfer.h"
+
+#include <time.h>
+
+/*
+** Maximum number of HTTP redirects that any http_exchange() call will
+** follow before throwing a fatal error. Most browsers use a limit of 20.
+*/
+#define MAX_REDIRECTS 20
+
+/*
+** This structure holds information about the current state of either
+** a client or a server that is participating in xfer.
+*/
+typedef struct Xfer Xfer;
+struct Xfer {
+  Blob *pIn;          /* Input text from the other side */
+  Blob *pOut;         /* Compose our reply here */
+  Blob line;          /* The current line of input */
+  Blob aToken[6];     /* Tokenized version of line */
+  Blob err;           /* Error message text */
+  int nToken;         /* Number of tokens in line */
+  int nIGotSent;      /* Number of "igot" cards sent */
+  int nPrivIGot;      /* Number of private "igot" cards */
+  int nGimmeSent;     /* Number of gimme cards sent */
+  int nFileSent;      /* Number of files sent */
+  int nDeltaSent;     /* Number of deltas sent */
+  int nFileRcvd;      /* Number of files received */
+  int nDeltaRcvd;     /* Number of deltas received */
+  int nDanglingFile;  /* Number of dangling deltas received */
+  int mxSend;         /* Stop sending "file" when pOut reaches this size */
+  int resync;         /* Send igot cards for all holdings */
+  u8 syncPrivate;     /* True to enable syncing private content */
+  u8 nextIsPrivate;   /* If true, next "file" received is a private */
+  u32 remoteVersion;  /* Version of fossil running on the other side */
+  u32 remoteDate;     /* Date for specific client software edition */
+  u32 remoteTime;     /* Time of date corresponding on remoteDate */
+  time_t maxTime;     /* Time when this transfer should be finished */
+};
+
+
+/*
+** The input blob contains an artifact.  Convert it into a record ID.
+** Create a phantom record if no prior record exists and
+** phantomize is true.
+**
+** Compare to uuid_to_rid().  This routine takes a blob argument
+** and does less error checking.
+*/
+static int rid_from_uuid(Blob *pUuid, int phantomize, int isPrivate){
+  static Stmt q;
+  int rid;
+
+  db_static_prepare(&q, "SELECT rid FROM blob WHERE uuid=:uuid");
+  db_bind_str(&q, ":uuid", pUuid);
+  if( db_step(&q)==SQLITE_ROW ){
+    rid = db_column_int(&q, 0);
+  }else{
+    rid = 0;
+  }
+  db_reset(&q);
+  if( rid==0 && phantomize ){
+    rid = content_new(blob_str(pUuid), isPrivate);
+  }
+  return rid;
+}
+
+/*
+** Remember that the other side of the connection already has a copy
+** of the file rid.
+*/
+static void remote_has(int rid){
+  if( rid ){
+    static Stmt q;
+    db_static_prepare(&q, "INSERT OR IGNORE INTO onremote VALUES(:r)");
+    db_bind_int(&q, ":r", rid);
+    db_step(&q);
+    db_reset(&q);
+  }
+}
+
+/*
+** Remember that the other side of the connection lacks a copy of
+** the artifact with the given hash.
+*/
+static void remote_unk(Blob *pHash){
+  static Stmt q;
+  db_static_prepare(&q, "INSERT OR IGNORE INTO unk VALUES(:h)");
+  db_bind_text(&q, ":h", blob_str(pHash));
+  db_step(&q);
+  db_reset(&q);
+}
+
+/*
+** The aToken[0..nToken-1] blob array is a parse of a "file" line
+** message.  This routine finishes parsing that message and does
+** a record insert of the file.
+**
+** The file line is in one of the following two forms:
+**
+**      file HASH SIZE \n CONTENT
+**      file HASH DELTASRC SIZE \n CONTENT
+**
+** The content is SIZE bytes immediately following the newline.
+** If DELTASRC exists, then the CONTENT is a delta against the
+** content of DELTASRC.
+**
+** If any error occurs, write a message into pErr which has already
+** be initialized to an empty string.
+**
+** Any artifact successfully received by this routine is considered to
+** be public and is therefore removed from the "private" table.
+*/
+static void xfer_accept_file(
+  Xfer *pXfer,
+  int cloneFlag,
+  char **pzUuidList,
+  int *pnUuidList
+){
+  int n;
+  int rid;
+  int srcid = 0;
+  Blob content;
+  int isPriv;
+  Blob *pUuid;
+
+  isPriv = pXfer->nextIsPrivate;
+  pXfer->nextIsPrivate = 0;
+  if( pXfer->nToken<3
+   || pXfer->nToken>4
+   || !blob_is_hname(&pXfer->aToken[1])
+   || !blob_is_int(&pXfer->aToken[pXfer->nToken-1], &n)
+   || n<0
+   || (pXfer->nToken==4 && !blob_is_hname(&pXfer->aToken[2]))
+  ){
+    blob_appendf(&pXfer->err, "malformed file line");
+    return;
+  }
+  blob_zero(&content);
+  blob_extract(pXfer->pIn, n, &content);
+  pUuid = &pXfer->aToken[1];
+  if( !cloneFlag && uuid_is_shunned(blob_str(pUuid)) ){
+    /* Ignore files that have been shunned */
+    blob_reset(&content);
+    return;
+  }
+  if( isPriv && !g.perm.Private ){
+    /* Do not accept private files if not authorized */
+    blob_reset(&content);
+    return;
+  }
+  if( cloneFlag ){
+    if( pXfer->nToken==4 ){
+      srcid = rid_from_uuid(&pXfer->aToken[2], 1, isPriv);
+      pXfer->nDeltaRcvd++;
+    }else{
+      srcid = 0;
+      pXfer->nFileRcvd++;
+    }
+    rid = content_put_ex(&content, blob_str(pUuid), srcid,
+                         0, isPriv);
+    Th_AppendToList(pzUuidList, pnUuidList, blob_str(pUuid),
+                    blob_size(pUuid));
+    remote_has(rid);
+    blob_reset(&content);
+    return;
+  }
+  if( pXfer->nToken==4 ){
+    Blob src, next;
+    srcid = rid_from_uuid(&pXfer->aToken[2], 1, isPriv);
+    if( content_get(srcid, &src)==0 ){
+      rid = content_put_ex(&content, blob_str(pUuid), srcid,
+                           0, isPriv);
+      Th_AppendToList(pzUuidList, pnUuidList, blob_str(pUuid),
+                      blob_size(pUuid));
+      pXfer->nDanglingFile++;
+      db_multi_exec("DELETE FROM phantom WHERE rid=%d", rid);
+      if( !isPriv ) content_make_public(rid);
+      blob_reset(&src);
+      blob_reset(&content);
+      return;
+    }
+    pXfer->nDeltaRcvd++;
+    blob_delta_apply(&src, &content, &next);
+    blob_reset(&src);
+    blob_reset(&content);
+    content = next;
+  }else{
+    pXfer->nFileRcvd++;
+  }
+  if( hname_verify_hash(&content, blob_buffer(pUuid), blob_size(pUuid))==0 ){
+    blob_appendf(&pXfer->err, "wrong hash on received artifact: %b", pUuid);
+  }
+  rid = content_put_ex(&content, blob_str(pUuid), 0, 0, isPriv);
+  Th_AppendToList(pzUuidList, pnUuidList, blob_str(pUuid), blob_size(pUuid));
+  if( rid==0 ){
+    blob_appendf(&pXfer->err, "%s", g.zErrMsg);
+    blob_reset(&content);
+  }else{
+    if( !isPriv ) content_make_public(rid);
+    manifest_crosslink(rid, &content, MC_NO_ERRORS);
+  }
+  assert( blob_is_reset(&content) );
+  remote_has(rid);
+}
+
+/*
+** The aToken[0..nToken-1] blob array is a parse of a "cfile" line
+** message.  This routine finishes parsing that message and does
+** a record insert of the file.  The difference between "file" and
+** "cfile" is that with "cfile" the content is already compressed.
+**
+** The file line is in one of the following two forms:
+**
+**      cfile HASH USIZE CSIZE \n CONTENT
+**      cfile HASH DELTASRC USIZE CSIZE \n CONTENT
+**
+** The content is CSIZE bytes immediately following the newline.
+** If DELTASRC exists, then the CONTENT is a delta against the
+** content of DELTASRC.
+**
+** The original size of the HASH artifact is USIZE.
+**
+** If any error occurs, write a message into pErr which has already
+** be initialized to an empty string.
+**
+** Any artifact successfully received by this routine is considered to
+** be public and is therefore removed from the "private" table.
+*/
+static void xfer_accept_compressed_file(
+  Xfer *pXfer,
+  char **pzUuidList,
+  int *pnUuidList
+){
+  int szC;   /* CSIZE */
+  int szU;   /* USIZE */
+  int rid;
+  int srcid = 0;
+  Blob content;
+  int isPriv;
+
+  isPriv = pXfer->nextIsPrivate;
+  pXfer->nextIsPrivate = 0;
+  if( pXfer->nToken<4
+   || pXfer->nToken>5
+   || !blob_is_hname(&pXfer->aToken[1])
+   || !blob_is_int(&pXfer->aToken[pXfer->nToken-2], &szU)
+   || !blob_is_int(&pXfer->aToken[pXfer->nToken-1], &szC)
+   || szC<0 || szU<0
+   || (pXfer->nToken==5 && !blob_is_hname(&pXfer->aToken[2]))
+  ){
+    blob_appendf(&pXfer->err, "malformed cfile line");
+    return;
+  }
+  if( isPriv && !g.perm.Private ){
+    /* Do not accept private files if not authorized */
+    return;
+  }
+  blob_zero(&content);
+  blob_extract(pXfer->pIn, szC, &content);
+  if( uuid_is_shunned(blob_str(&pXfer->aToken[1])) ){
+    /* Ignore files that have been shunned */
+    blob_reset(&content);
+    return;
+  }
+  if( pXfer->nToken==5 ){
+    srcid = rid_from_uuid(&pXfer->aToken[2], 1, isPriv);
+    pXfer->nDeltaRcvd++;
+  }else{
+    srcid = 0;
+    pXfer->nFileRcvd++;
+  }
+  rid = content_put_ex(&content, blob_str(&pXfer->aToken[1]), srcid,
+                       szC, isPriv);
+  Th_AppendToList(pzUuidList, pnUuidList, blob_str(&pXfer->aToken[1]),
+                  blob_size(&pXfer->aToken[1]));
+  remote_has(rid);
+  blob_reset(&content);
+}
+
+/*
+** The aToken[0..nToken-1] blob array is a parse of a "uvfile" line
+** message.  This routine finishes parsing that message and adds the
+** unversioned file to the "unversioned" table.
+**
+** The file line is in one of the following two forms:
+**
+**      uvfile NAME MTIME HASH SIZE FLAGS
+**      uvfile NAME MTIME HASH SIZE FLAGS \n CONTENT
+**
+** If the 0x0001 bit of FLAGS is set, that means the file has been
+** deleted, SIZE is zero, the HASH is "-", and the "\n CONTENT" is omitted.
+**
+** SIZE is the number of bytes of CONTENT.  The CONTENT is uncompressed.
+** HASH is the artifact hash of CONTENT.
+**
+** If the 0x0004 bit of FLAGS is set, that means the CONTENT is omitted.
+** The sender might have omitted the content because it is too big to
+** transmit, or because it is unchanged and this record exists purely
+** to update the MTIME.
+*/
+static void xfer_accept_unversioned_file(Xfer *pXfer, int isWriter){
+  sqlite3_int64 mtime;    /* The MTIME */
+  Blob *pHash;            /* The HASH value */
+  int sz;                 /* The SIZE */
+  int flags;              /* The FLAGS */
+  Blob content;           /* The CONTENT */
+  Blob x;                 /* Compressed content */
+  Stmt q;                 /* SQL statements for comparison and insert */
+  int isDelete;           /* HASH is "-" indicating this is a delete */
+  int nullContent;        /* True of CONTENT is NULL */
+  int iStatus;            /* Result from unversioned_status() */
+
+  pHash = &pXfer->aToken[3];
+  if( pXfer->nToken==5
+   || !blob_is_filename(&pXfer->aToken[1])
+   || !blob_is_int64(&pXfer->aToken[2], &mtime)
+   || (!blob_eq(pHash,"-") && !blob_is_hname(pHash))
+   || !blob_is_int(&pXfer->aToken[4], &sz)
+   || !blob_is_int(&pXfer->aToken[5], &flags)
+   || (mtime<0 || sz<0 || flags<0)
+  ){
+    blob_appendf(&pXfer->err, "malformed uvfile line");
+    return;
+  }
+  blob_init(&content, 0, 0);
+  blob_init(&x, 0, 0);
+  if( sz>0 && (flags & 0x0005)==0 ){
+    blob_extract(pXfer->pIn, sz, &content);
+    nullContent = 0;
+    if( hname_verify_hash(&content, blob_buffer(pHash), blob_size(pHash))==0 ){
+      blob_appendf(&pXfer->err, "in uvfile line, HASH does not match CONTENT");
+      goto end_accept_unversioned_file;
+    }
+  }else{
+    nullContent = 1;
+  }
+
+  /* The isWriter flag must be true in order to land the new file */
+  if( !isWriter ){
+    blob_appendf(&pXfer->err,"Write permissions for unversioned files missing");
+    goto end_accept_unversioned_file;
+  }
+
+  /* Make sure we have a valid g.rcvid marker */
+  content_rcvid_init(0);
+
+  /* Check to see if current content really should be overwritten.  Ideally,
+  ** a uvfile card should never have been sent unless the overwrite should
+  ** occur.  But do not trust the sender.  Double-check.
+  */
+  iStatus = unversioned_status(blob_str(&pXfer->aToken[1]), mtime,
+                               blob_str(pHash));
+  if( iStatus>=3 ) goto end_accept_unversioned_file;
+
+  /* Store the content */
+  isDelete = blob_eq(pHash, "-");
+  if( isDelete ){
+    db_prepare(&q,
+      "UPDATE unversioned"
+      "   SET rcvid=:rcvid, mtime=:mtime, hash=NULL,"
+      "       sz=0, encoding=0, content=NULL"
+      " WHERE name=:name"
+    );
+    db_bind_int(&q, ":rcvid", g.rcvid);
+  }else if( iStatus==2 ){
+    db_prepare(&q, "UPDATE unversioned SET mtime=:mtime WHERE name=:name");
+  }else{
+    db_prepare(&q,
+      "REPLACE INTO unversioned(name,rcvid,mtime,hash,sz,encoding,content)"
+      " VALUES(:name,:rcvid,:mtime,:hash,:sz,:encoding,:content)"
+    );
+    db_bind_int(&q, ":rcvid", g.rcvid);
+    db_bind_text(&q, ":hash", blob_str(pHash));
+    db_bind_int(&q, ":sz", blob_size(&content));
+    if( !nullContent ){
+      blob_compress(&content, &x);
+      if( blob_size(&x) < 0.8*blob_size(&content) ){
+        db_bind_blob(&q, ":content", &x);
+        db_bind_int(&q, ":encoding", 1);
+      }else{
+        db_bind_blob(&q, ":content", &content);
+        db_bind_int(&q, ":encoding", 0);
+      }
+    }else{
+      db_bind_int(&q, ":encoding", 0);
+    }
+  }
+  db_bind_text(&q, ":name", blob_str(&pXfer->aToken[1]));
+  db_bind_int64(&q, ":mtime", mtime);
+  db_step(&q);
+  db_finalize(&q);
+  db_unset("uv-hash", 0);
+
+end_accept_unversioned_file:
+  blob_reset(&x);
+  blob_reset(&content);
+}
+
+/*
+** Try to send a file as a delta against its parent.
+** If successful, return the number of bytes in the delta.
+** If we cannot generate an appropriate delta, then send
+** nothing and return zero.
+**
+** Never send a delta against a private artifact.
+*/
+static int send_delta_parent(
+  Xfer *pXfer,            /* The transfer context */
+  int rid,                /* record id of the file to send */
+  int isPrivate,          /* True if rid is a private artifact */
+  Blob *pContent,         /* The content of the file to send */
+  Blob *pUuid             /* The HASH of the file to send */
+){
+  static const char *const azQuery[] = {
+    "SELECT pid FROM plink x"
+    " WHERE cid=%d"
+    "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=pid)",
+
+    "SELECT pid, min(mtime) FROM mlink, event ON mlink.mid=event.objid"
+    " WHERE fid=%d"
+    "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=pid)"
+  };
+  int i;
+  Blob src, delta;
+  int size = 0;
+  int srcId = 0;
+
+  for(i=0; srcId==0 && i<count(azQuery); i++){
+    srcId = db_int(0, azQuery[i] /*works-like:"%d"*/, rid);
+  }
+  if( srcId>0
+   && (pXfer->syncPrivate || !content_is_private(srcId))
+   && content_get(srcId, &src)
+  ){
+    char *zUuid = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", srcId);
+    blob_delta_create(&src, pContent, &delta);
+    size = blob_size(&delta);
+    if( size>=(int)blob_size(pContent)-50 ){
+      size = 0;
+    }else if( uuid_is_shunned(zUuid) ){
+      size = 0;
+    }else{
+       if( isPrivate ) blob_append(pXfer->pOut, "private\n", -1);
+      blob_appendf(pXfer->pOut, "file %b %s %d\n", pUuid, zUuid, size);
+      blob_append(pXfer->pOut, blob_buffer(&delta), size);
+    }
+    blob_reset(&delta);
+    free(zUuid);
+    blob_reset(&src);
+  }
+  return size;
+}
+
+/*
+** Try to send a file as a native delta.
+** If successful, return the number of bytes in the delta.
+** If we cannot generate an appropriate delta, then send
+** nothing and return zero.
+**
+** Never send a delta against a private artifact.
+*/
+static int send_delta_native(
+  Xfer *pXfer,            /* The transfer context */
+  int rid,                /* record id of the file to send */
+  int isPrivate,          /* True if rid is a private artifact */
+  Blob *pUuid             /* The HASH of the file to send */
+){
+  Blob src, delta;
+  int size = 0;
+  int srcId;
+
+  srcId = db_int(0, "SELECT srcid FROM delta WHERE rid=%d", rid);
+  if( srcId>0
+   && (pXfer->syncPrivate || !content_is_private(srcId))
+  ){
+    blob_zero(&src);
+    db_blob(&src, "SELECT uuid FROM blob WHERE rid=%d", srcId);
+    if( uuid_is_shunned(blob_str(&src)) ){
+      blob_reset(&src);
+      return 0;
+    }
+    blob_zero(&delta);
+    db_blob(&delta, "SELECT content FROM blob WHERE rid=%d", rid);
+    blob_uncompress(&delta, &delta);
+    if( isPrivate ) blob_append(pXfer->pOut, "private\n", -1);
+    blob_appendf(pXfer->pOut, "file %b %b %d\n",
+                pUuid, &src, blob_size(&delta));
+    blob_append(pXfer->pOut, blob_buffer(&delta), blob_size(&delta));
+    size = blob_size(&delta);
+    blob_reset(&delta);
+    blob_reset(&src);
+  }else{
+    size = 0;
+  }
+  return size;
+}
+
+/*
+** Push an error message to alert the older client that the repository
+** has SHA3 content and cannot be synced or cloned.
+*/
+static void xfer_cannot_send_sha3_error(Xfer *pXfer){
+  blob_appendf(pXfer->pOut,
+    "error Fossil\\sversion\\s2.0\\sor\\slater\\srequired.\n"
+  );
+}
+
+
+/*
+** Send the file identified by rid.
+**
+** The pUuid can be NULL in which case the correct hash is computed
+** from the rid.
+**
+** Try to send the file as a native delta if nativeDelta is true, or
+** as a parent delta if nativeDelta is false.
+**
+** It should never be the case that rid is a private artifact.  But
+** as a precaution, this routine does check on rid and if it is private
+** this routine becomes a no-op.
+*/
+static void send_file(Xfer *pXfer, int rid, Blob *pUuid, int nativeDelta){
+  Blob content, uuid;
+  int size = 0;
+  int isPriv = content_is_private(rid);
+
+  if( isPriv && pXfer->syncPrivate==0 ){
+    if( pXfer->remoteDate>=20200413 && pUuid && blob_size(pUuid)>0 ){
+      /* If the artifact is private and we are not doing a private sync,
+      ** at least tell the other side that the artifact exists and is
+      ** known to be private.  But only do this for newer clients since
+      ** older ones will throw an error if they get a private igot card
+      ** and private syncing is disallowed */
+      blob_appendf(pXfer->pOut, "igot %b 1\n", pUuid);
+      pXfer->nIGotSent++;
+      pXfer->nPrivIGot++;
+    }
+    return;
+  }
+  if( db_exists("SELECT 1 FROM onremote WHERE rid=%d", rid) ){
+     return;
+  }
+  blob_zero(&uuid);
+  db_blob(&uuid, "SELECT uuid FROM blob WHERE rid=%d AND size>=0", rid);
+  if( blob_size(&uuid)==0 ){
+    return;
+  }
+  if( blob_size(&uuid)>HNAME_LEN_SHA1 && pXfer->remoteVersion<20000 ){
+    xfer_cannot_send_sha3_error(pXfer);
+    return;
+  }
+  if( pUuid ){
+    if( blob_compare(pUuid, &uuid)!=0 ){
+      blob_reset(&uuid);
+      return;
+    }
+  }else{
+    pUuid = &uuid;
+  }
+  if( uuid_is_shunned(blob_str(pUuid)) ){
+    blob_reset(&uuid);
+    return;
+  }
+  if( (pXfer->maxTime != -1 && time(NULL) >= pXfer->maxTime) ||
+       pXfer->mxSend<=(int)blob_size(pXfer->pOut) ){
+    const char *zFormat = isPriv ? "igot %b 1\n" : "igot %b\n";
+    blob_appendf(pXfer->pOut, zFormat /*works-like:"%b"*/, pUuid);
+    pXfer->nIGotSent++;
+    blob_reset(&uuid);
+    return;
+  }
+  if( nativeDelta ){
+    size = send_delta_native(pXfer, rid, isPriv, pUuid);
+    if( size ){
+      pXfer->nDeltaSent++;
+    }
+  }
+  if( size==0 ){
+    content_get(rid, &content);
+
+    if( !nativeDelta && blob_size(&content)>100 ){
+      size = send_delta_parent(pXfer, rid, isPriv, &content, pUuid);
+    }
+    if( size==0 ){
+      int size = blob_size(&content);
+      if( isPriv ) blob_append(pXfer->pOut, "private\n", -1);
+      blob_appendf(pXfer->pOut, "file %b %d\n", pUuid, size);
+      blob_append(pXfer->pOut, blob_buffer(&content), size);
+      pXfer->nFileSent++;
+    }else{
+      pXfer->nDeltaSent++;
+    }
+    blob_reset(&content);
+  }
+  remote_has(rid);
+  blob_reset(&uuid);
+#if 0
+  if( blob_buffer(pXfer->pOut)[blob_size(pXfer->pOut)-1]!='\n' ){
+    blob_append(pXfer->pOut, "\n", 1);
+  }
+#endif
+}
+
+/*
+** Send the file identified by rid as a compressed artifact.  Basically,
+** send the content exactly as it appears in the BLOB table using
+** a "cfile" card.
+*/
+static void send_compressed_file(Xfer *pXfer, int rid){
+  const char *zContent;
+  const char *zUuid;
+  const char *zDelta;
+  int szU;
+  int szC;
+  int rc;
+  int isPrivate;
+  int srcIsPrivate;
+  static Stmt q1;
+  Blob fullContent;
+
+  isPrivate = content_is_private(rid);
+  if( isPrivate && pXfer->syncPrivate==0 ) return;
+  db_static_prepare(&q1,
+    "SELECT uuid, size, content, delta.srcid IN private,"
+         "  (SELECT uuid FROM blob WHERE rid=delta.srcid)"
+    " FROM blob LEFT JOIN delta ON (blob.rid=delta.rid)"
+    " WHERE blob.rid=:rid"
+    "   AND blob.size>=0"
+    "   AND NOT EXISTS(SELECT 1 FROM shun WHERE shun.uuid=blob.uuid)"
+  );
+  db_bind_int(&q1, ":rid", rid);
+  rc = db_step(&q1);
+  if( rc==SQLITE_ROW ){
+    zUuid = db_column_text(&q1, 0);
+    szU = db_column_int(&q1, 1);
+    szC = db_column_bytes(&q1, 2);
+    zContent = db_column_raw(&q1, 2);
+    srcIsPrivate = db_column_int(&q1, 3);
+    zDelta = db_column_text(&q1, 4);
+    if( isPrivate ) blob_append(pXfer->pOut, "private\n", -1);
+    if( pXfer->remoteVersion<20000 && db_column_bytes(&q1,0)!=HNAME_LEN_SHA1 ){
+      xfer_cannot_send_sha3_error(pXfer);
+      db_reset(&q1);
+      return;
+    }
+    blob_appendf(pXfer->pOut, "cfile %s ", zUuid);
+    if( !isPrivate && srcIsPrivate ){
+      content_get(rid, &fullContent);
+      szU = blob_size(&fullContent);
+      blob_compress(&fullContent, &fullContent);
+      szC = blob_size(&fullContent);
+      zContent = blob_buffer(&fullContent);
+      zDelta = 0;
+    }
+    if( zDelta ){
+      blob_appendf(pXfer->pOut, "%s ", zDelta);
+      pXfer->nDeltaSent++;
+    }else{
+      pXfer->nFileSent++;
+    }
+    blob_appendf(pXfer->pOut, "%d %d\n", szU, szC);
+    blob_append(pXfer->pOut, zContent, szC);
+    if( blob_buffer(pXfer->pOut)[blob_size(pXfer->pOut)-1]!='\n' ){
+      blob_append(pXfer->pOut, "\n", 1);
+    }
+    if( !isPrivate && srcIsPrivate ){
+      blob_reset(&fullContent);
+    }
+  }
+  db_reset(&q1);
+}
+
+/*
+** Send the unversioned file identified by zName by generating the
+** appropriate "uvfile" card.
+**
+**     uvfile NAME MTIME HASH SIZE FLAGS \n CONTENT
+**
+** If the noContent flag is set, omit the CONTENT and set the 0x0004
+** flag in FLAGS.
+*/
+static void send_unversioned_file(
+  Xfer *pXfer,            /* Transfer context */
+  const char *zName,      /* Name of unversioned file to be sent */
+  int noContent           /* True to omit the content */
+){
+  Stmt q1;
+
+  if( (int)blob_size(pXfer->pOut)>=pXfer->mxSend ) noContent = 1;
+  if( noContent ){
+    db_prepare(&q1,
+      "SELECT mtime, hash, encoding, sz FROM unversioned WHERE name=%Q",
+      zName
+    );
+  }else{
+    db_prepare(&q1,
+      "SELECT mtime, hash, encoding, sz, content FROM unversioned"
+      " WHERE name=%Q",
+      zName
+    );
+  }
+  if( db_step(&q1)==SQLITE_ROW ){
+    sqlite3_int64 mtime = db_column_int64(&q1, 0);
+    const char *zHash = db_column_text(&q1, 1);
+    if( pXfer->remoteVersion<20000 && db_column_bytes(&q1,1)>HNAME_LEN_SHA1 ){
+      xfer_cannot_send_sha3_error(pXfer);
+      db_reset(&q1);
+      return;
+    }
+    if( (int)blob_size(pXfer->pOut)>=pXfer->mxSend ){
+      /* If we have already reached the send size limit, send a (short)
+      ** uvigot card rather than a uvfile card.  This only happens on the
+      ** server side.  The uvigot card will provoke the client to resend
+      ** another uvgimme on the next cycle. */
+      blob_appendf(pXfer->pOut, "uvigot %s %lld %s %d\n",
+                   zName, mtime, zHash, db_column_int(&q1,3));
+    }else{
+      blob_appendf(pXfer->pOut, "uvfile %s %lld", zName, mtime);
+      if( zHash==0 ){
+        blob_append(pXfer->pOut, " - 0 1\n", -1);
+      }else if( noContent ){
+        blob_appendf(pXfer->pOut, " %s %d 4\n", zHash, db_column_int(&q1,3));
+      }else{
+        Blob content;
+        blob_init(&content, 0, 0);
+        db_column_blob(&q1, 4, &content);
+        if( db_column_int(&q1, 2) ){
+          blob_uncompress(&content, &content);
+        }
+        blob_appendf(pXfer->pOut, " %s %d 0\n", zHash, blob_size(&content));
+        blob_append(pXfer->pOut, blob_buffer(&content), blob_size(&content));
+        blob_reset(&content);
+      }
+    }
+  }
+  db_finalize(&q1);
+}
+
+/*
+** Send a gimme message for every phantom.
+**
+** Except: do not request shunned artifacts.  And do not request
+** private artifacts if we are not doing a private transfer.
+*/
+static void request_phantoms(Xfer *pXfer, int maxReq){
+  Stmt q;
+  db_prepare(&q,
+    "SELECT uuid FROM phantom CROSS JOIN blob USING(rid) /*scan*/"
+    " WHERE NOT EXISTS(SELECT 1 FROM unk WHERE unk.uuid=blob.uuid)"
+    "   AND NOT EXISTS(SELECT 1 FROM shun WHERE uuid=blob.uuid) %s",
+    (pXfer->syncPrivate ? "" :
+         "   AND NOT EXISTS(SELECT 1 FROM private WHERE rid=blob.rid)")
+  );
+  while( db_step(&q)==SQLITE_ROW && maxReq-- > 0 ){
+    const char *zUuid = db_column_text(&q, 0);
+    blob_appendf(pXfer->pOut, "gimme %s\n", zUuid);
+    pXfer->nGimmeSent++;
+  }
+  db_finalize(&q);
+}
+
+/*
+** Compute an hash on the tail of pMsg.  Verify that it matches the
+** the hash given in pHash.  Return non-zero for an error and 0 on success.
+**
+** The type of hash computed (SHA1, SHA3-256) is determined by
+** the length of the input hash in pHash.
+*/
+static int check_tail_hash(Blob *pHash, Blob *pMsg){
+  Blob tail;
+  int rc;
+  blob_tail(pMsg, &tail);
+  rc = hname_verify_hash(&tail, blob_buffer(pHash), blob_size(pHash));
+  blob_reset(&tail);
+  return rc==HNAME_ERROR;
+}
+
+/*
+** Check the signature on an application/x-fossil payload received by
+** the HTTP server.  The signature is a line of the following form:
+**
+**        login LOGIN NONCE SIGNATURE
+**
+** The NONCE is the SHA1 hash of the remainder of the input.
+** SIGNATURE is the SHA1 checksum of the NONCE concatenated
+** with the sha1_shared_secret() encoding of the users password.
+**
+**   SIGNATURE = sha1_sum( NONCE + sha1_shared_secret(PASSWORD) );
+**
+** The parameters to this routine are ephemeral blobs holding the
+** LOGIN, NONCE and SIGNATURE.
+**
+** This routine attempts to locate the user and verify the signature.
+** If everything checks out, the USER.CAP column for the USER table
+** is consulted to set privileges in the global g variable.
+**
+** If anything fails to check out, no changes are made to privileges.
+**
+** Signature generation on the client side is handled by the
+** http_exchange() routine.
+**
+** Return non-zero for a login failure and zero for success.
+*/
+static int check_login(Blob *pLogin, Blob *pNonce, Blob *pSig){
+  Stmt q;
+  int rc = -1;
+  char *zLogin = blob_terminate(pLogin);
+  defossilize(zLogin);
+
+  if( fossil_strcmp(zLogin, "nobody")==0
+   || fossil_strcmp(zLogin, "anonymous")==0
+  ){
+    return 0;   /* Anybody is allowed to sync as "nobody" or "anonymous" */
+  }
+  if( fossil_strcmp(P("REMOTE_USER"), zLogin)==0
+      && db_get_boolean("remote_user_ok",0) ){
+    return 0;   /* Accept Basic Authorization */
+  }
+  db_prepare(&q,
+     "SELECT pw, cap, uid FROM user"
+     " WHERE login=%Q"
+     "   AND login NOT IN ('anonymous','nobody','developer','reader')"
+     "   AND length(pw)>0",
+     zLogin
+  );
+  if( db_step(&q)==SQLITE_ROW ){
+    int szPw;
+    Blob pw, combined, hash;
+    blob_zero(&pw);
+    db_ephemeral_blob(&q, 0, &pw);
+    szPw = blob_size(&pw);
+    blob_zero(&combined);
+    blob_copy(&combined, pNonce);
+    blob_append(&combined, blob_buffer(&pw), szPw);
+    sha1sum_blob(&combined, &hash);
+    assert( blob_size(&hash)==40 );
+    rc = blob_constant_time_cmp(&hash, pSig);
+    blob_reset(&hash);
+    blob_reset(&combined);
+    if( rc!=0 && szPw!=40 ){
+      /* If this server stores cleartext passwords and the password did not
+      ** match, then perhaps the client is sending SHA1 passwords.  Try
+      ** again with the SHA1 password.
+      */
+      const char *zPw = db_column_text(&q, 0);
+      char *zSecret = sha1_shared_secret(zPw, blob_str(pLogin), 0);
+      blob_zero(&combined);
+      blob_copy(&combined, pNonce);
+      blob_append(&combined, zSecret, -1);
+      fossil_free(zSecret);
+      sha1sum_blob(&combined, &hash);
+      rc = blob_constant_time_cmp(&hash, pSig);
+      blob_reset(&hash);
+      blob_reset(&combined);
+    }
+    if( rc==0 ){
+      const char *zCap;
+      zCap = db_column_text(&q, 1);
+      login_set_capabilities(zCap, 0);
+      g.userUid = db_column_int(&q, 2);
+      g.zLogin = mprintf("%b", pLogin);
+      g.zNonce = mprintf("%b", pNonce);
+    }
+  }
+  db_finalize(&q);
+  return rc;
+}
+
+/*
+** Send the content of all files in the unsent table.
+**
+** This is really just an optimization.  If you clear the
+** unsent table, all the right files will still get transferred.
+** It just might require an extra round trip or two.
+*/
+static void send_unsent(Xfer *pXfer){
+  Stmt q;
+  db_prepare(&q, "SELECT rid FROM unsent EXCEPT SELECT rid FROM private");
+  while( db_step(&q)==SQLITE_ROW ){
+    int rid = db_column_int(&q, 0);
+    send_file(pXfer, rid, 0, 0);
+  }
+  db_finalize(&q);
+  db_multi_exec("DELETE FROM unsent");
+}
+
+/*
+** Check to see if the number of unclustered entries is greater than
+** 100 and if it is, form a new cluster.  Unclustered phantoms do not
+** count toward the 100 total.  And phantoms are never added to a new
+** cluster.
+*/
+void create_cluster(void){
+  Blob cluster, cksum;
+  Blob deleteWhere;
+  Stmt q;
+  int nUncl;
+  int nRow = 0;
+  int rid;
+
+#if 0
+  /* We should not ever get any private artifacts in the unclustered table.
+  ** But if we do (because of a bug) now is a good time to delete them. */
+  db_multi_exec(
+    "DELETE FROM unclustered WHERE rid IN (SELECT rid FROM private)"
+  );
+#endif
+
+  nUncl = db_int(0, "SELECT count(*) FROM unclustered /*scan*/"
+                    " WHERE NOT EXISTS(SELECT 1 FROM phantom"
+                                      " WHERE rid=unclustered.rid)");
+  if( nUncl>=100 ){
+    blob_zero(&cluster);
+    blob_zero(&deleteWhere);
+    db_prepare(&q, "SELECT uuid FROM unclustered, blob"
+                   " WHERE NOT EXISTS(SELECT 1 FROM phantom"
+                   "                   WHERE rid=unclustered.rid)"
+                   "   AND unclustered.rid=blob.rid"
+                   "   AND NOT EXISTS(SELECT 1 FROM shun WHERE uuid=blob.uuid)"
+                   " ORDER BY 1");
+    while( db_step(&q)==SQLITE_ROW ){
+      blob_appendf(&cluster, "M %s\n", db_column_text(&q, 0));
+      nRow++;
+      if( nRow>=800 && nUncl>nRow+100 ){
+        md5sum_blob(&cluster, &cksum);
+        blob_appendf(&cluster, "Z %b\n", &cksum);
+        blob_reset(&cksum);
+        rid = content_put(&cluster);
+        manifest_crosslink(rid, &cluster, MC_NONE);
+        blob_reset(&cluster);
+        nUncl -= nRow;
+        nRow = 0;
+        blob_append_sql(&deleteWhere, ",%d", rid);
+      }
+    }
+    db_finalize(&q);
+    db_multi_exec(
+      "DELETE FROM unclustered WHERE rid NOT IN (0 %s)"
+      "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=unclustered.rid)",
+      blob_sql_text(&deleteWhere)
+    );
+    blob_reset(&deleteWhere);
+    if( nRow>0 ){
+      md5sum_blob(&cluster, &cksum);
+      blob_appendf(&cluster, "Z %b\n", &cksum);
+      blob_reset(&cksum);
+      rid = content_put(&cluster);
+      manifest_crosslink(rid, &cluster, MC_NONE);
+      blob_reset(&cluster);
+    }
+  }
+}
+
+/*
+** Send igot messages for every private artifact
+*/
+static int send_private(Xfer *pXfer){
+  int cnt = 0;
+  Stmt q;
+  if( pXfer->syncPrivate ){
+    db_prepare(&q, "SELECT uuid FROM private JOIN blob USING(rid)");
+    while( db_step(&q)==SQLITE_ROW ){
+      blob_appendf(pXfer->pOut, "igot %s 1\n", db_column_text(&q,0));
+      cnt++;
+    }
+    db_finalize(&q);
+  }
+  return cnt;
+}
+
+/*
+** Send an igot message for every entry in unclustered table.
+** Return the number of cards sent.
+**
+** Except:
+**    *  Do not send igot cards for shunned artifacts
+**    *  Do not send igot cards for phantoms
+**    *  Do not send igot cards for private artifacts
+**    *  Do not send igot cards for any artifact that is in the
+**       ONREMOTE table, if that table exists.
+**
+** If the pXfer->resync flag is set, that means we are doing a "--verily"
+** sync and all artifacts that don't meet the restrictions above should
+** be sent.
+*/
+static int send_unclustered(Xfer *pXfer){
+  Stmt q;
+  int cnt = 0;
+  const char *zExtra;
+  if( db_table_exists("temp","onremote") ){
+    zExtra = " AND NOT EXISTS(SELECT 1 FROM onremote WHERE rid=blob.rid)";
+  }else{
+    zExtra = "";
+  }
+  if( pXfer->resync ){
+    db_prepare(&q,
+      "SELECT uuid, rid FROM blob"
+      " WHERE NOT EXISTS(SELECT 1 FROM shun WHERE uuid=blob.uuid)"
+      "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=blob.rid)"
+      "   AND NOT EXISTS(SELECT 1 FROM private WHERE rid=blob.rid)%s"
+      "   AND blob.rid<=%d"
+      " ORDER BY blob.rid DESC",
+      zExtra /*safe-for-%s*/, pXfer->resync
+    );
+  }else{
+    db_prepare(&q,
+      "SELECT uuid FROM unclustered JOIN blob USING(rid) /*scan*/"
+      " WHERE NOT EXISTS(SELECT 1 FROM shun WHERE uuid=blob.uuid)"
+      "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=blob.rid)"
+      "   AND NOT EXISTS(SELECT 1 FROM private WHERE rid=blob.rid)%s",
+      zExtra /*safe-for-%s*/
+    );
+  }
+  while( db_step(&q)==SQLITE_ROW ){
+    blob_appendf(pXfer->pOut, "igot %s\n", db_column_text(&q, 0));
+    cnt++;
+    if( pXfer->resync && pXfer->mxSend<(int)blob_size(pXfer->pOut) ){
+      pXfer->resync = db_column_int(&q, 1)-1;
+    }
+  }
+  db_finalize(&q);
+  if( cnt==0 ) pXfer->resync = 0;
+  return cnt;
+}
+
+/*
+** Send an igot message for every cluster artifact that is not a phantom,
+** is not shunned, is not private, and that is not in the UNCLUSTERED table.
+** Return the number of cards sent.
+*/
+static int send_all_clusters(Xfer *pXfer){
+  Stmt q;
+  int cnt = 0;
+  const char *zExtra;
+  if( db_table_exists("temp","onremote") ){
+    zExtra = " AND NOT EXISTS(SELECT 1 FROM onremote WHERE rid=blob.rid)";
+  }else{
+    zExtra = "";
+  }
+  db_prepare(&q,
+    "SELECT uuid"
+    "  FROM tagxref JOIN blob ON tagxref.rid=blob.rid AND tagxref.tagid=%d"
+    " WHERE NOT EXISTS(SELECT 1 FROM shun WHERE uuid=blob.uuid)"
+    "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=blob.rid)"
+    "   AND NOT EXISTS(SELECT 1 FROM unclustered WHERE rid=blob.rid)"
+    "   AND NOT EXISTS(SELECT 1 FROM private WHERE rid=blob.rid)%s",
+    TAG_CLUSTER, zExtra /*safe-for-%s*/
+  );
+  while( db_step(&q)==SQLITE_ROW ){
+    if( cnt==0 ) blob_appendf(pXfer->pOut, "# sending-clusters\n");
+    blob_appendf(pXfer->pOut, "igot %s\n", db_column_text(&q, 0));
+    cnt++;
+  }
+  db_finalize(&q);
+  if( cnt ) blob_appendf(pXfer->pOut, "# end-of-clusters\n");
+  return cnt;
+}
+
+/*
+** Send an igot message for every artifact.
+*/
+static void send_all(Xfer *pXfer){
+  Stmt q;
+  db_prepare(&q,
+    "SELECT uuid FROM blob "
+    " WHERE NOT EXISTS(SELECT 1 FROM shun WHERE uuid=blob.uuid)"
+    "   AND NOT EXISTS(SELECT 1 FROM private WHERE rid=blob.rid)"
+    "   AND NOT EXISTS(SELECT 1 FROM phantom WHERE rid=blob.rid)"
+  );
+  while( db_step(&q)==SQLITE_ROW ){
+    blob_appendf(pXfer->pOut, "igot %s\n", db_column_text(&q, 0));
+  }
+  db_finalize(&q);
+}
+
+/*
+** pXfer is a "pragma uv-hash HASH" card.
+**
+** If HASH is different from the unversioned content hash on this server,
+** then send a bunch of uvigot cards, one for each entry unversioned file
+** on this server.
+*/
+static void send_unversioned_catalog(Xfer *pXfer){
+  Stmt uvq;
+  unversioned_schema();
+  db_prepare(&uvq,
+     "SELECT name, mtime, hash, sz FROM unversioned"
+  );
+  while( db_step(&uvq)==SQLITE_ROW ){
+    const char *zName = db_column_text(&uvq,0);
+    sqlite3_int64 mtime = db_column_int64(&uvq,1);
+    const char *zHash = db_column_text(&uvq,2);
+    int sz = db_column_int(&uvq,3);
+    if( zHash==0 ){ sz = 0; zHash = "-"; }
+    blob_appendf(pXfer->pOut, "uvigot %s %lld %s %d\n",
+                 zName, mtime, zHash, sz);
+  }
+  db_finalize(&uvq);
+}
+
+/*
+** Return a string that contains supplemental information about a
+** "not authorized" error.  The string might be empty if no additional
+** information is available.
+*/
+static char *whyNotAuth(void){
+  if( g.useLocalauth && db_get_boolean("localauth",0)!=0 ){
+    return "\\sbecause\\sthe\\s'localauth'\\ssetting\\sis\\senabled";
+  }
+  return "";
+}
+
+/*
+** Called when there is an attempt to transfer private content to and
+** from a server without authorization.
+*/
+static void server_private_xfer_not_authorized(void){
+  @ error not\sauthorized\sto\ssync\sprivate\scontent%s(whyNotAuth())
+}
+
+/*
+** Return the common TH1 code to evaluate prior to evaluating any other
+** TH1 transfer notification scripts.
+*/
+const char *xfer_common_code(void){
+  return db_get("xfer-common-script", 0);
+}
+
+/*
+** Return the TH1 code to evaluate when a push is processed.
+*/
+const char *xfer_push_code(void){
+  return db_get("xfer-push-script", 0);
+}
+
+/*
+** Return the TH1 code to evaluate when a commit is processed.
+*/
+const char *xfer_commit_code(void){
+  return db_get("xfer-commit-script", 0);
+}
+
+/*
+** Return the TH1 code to evaluate when a ticket change is processed.
+*/
+const char *xfer_ticket_code(void){
+  return db_get("xfer-ticket-script", 0);
+}
+
+/*
+** Reset the CGI content, roll back any pending db transaction, and
+** emit an "error" xfer message. The message text gets fossil-encoded
+** by this function. This is only intended for use with
+** fail-fast/fatal errors, not ones which can be skipped over.
+*/
+static void xfer_fatal_error(const char *zMsg){
+  cgi_reset_content();
+  if( db_transaction_nesting_depth()>0 ){
+    db_rollback_transaction();
+  }
+  @ error %F(zMsg)
+}
+
+/*
+** Run the specified TH1 script, if any, and returns 1 on error.
+*/
+int xfer_run_script(
+  const char *zScript,
+  const char *zUuidOrList,
+  int bIsList
+){
+  int rc = TH_OK;
+  if( !zScript ) return rc;
+  Th_FossilInit(TH_INIT_DEFAULT);
+  Th_Store(bIsList ? "uuids" : "uuid", zUuidOrList ? zUuidOrList : "");
+  rc = Th_Eval(g.interp, 0, zScript, -1);
+  if( rc!=TH_OK ){
+    fossil_error(1, "%s", Th_GetResult(g.interp, 0));
+  }
+  return rc;
+}
+
+/*
+** Runs the pre-transfer TH1 script, if any, and returns its return code.
+** This script may be run multiple times.  If the script performs actions
+** that cannot be redone, it should use an internal [if] guard similar to
+** the following:
+**
+** if {![info exists common_done]} {
+**   # ... code here
+**   set common_done 1
+** }
+*/
+int xfer_run_common_script(void){
+  return xfer_run_script(xfer_common_code(), 0, 0);
+}
+
+/*
+** This routine makes a "syncwith:URL" entry in the CONFIG table to
+** indicate that a sync is occurring with zUrl.
+**
+** Add a "syncfrom:URL" entry instead of "syncwith:URL" if bSyncFrom is true.
+*/
+static void xfer_syncwith(const char *zUrl, int bSyncFrom){
+  UrlData x;
+  memset(&x, 0, sizeof(x));
+  url_parse_local(zUrl, URL_OMIT_USER, &x);
+  if( x.protocol && strncmp(x.protocol,"http",4)==0
+   && x.name && sqlite3_strlike("%localhost%", x.name, 0)!=0
+  ){
+    db_unprotect(PROTECT_CONFIG);
+    db_multi_exec("REPLACE INTO config(name,value,mtime)"
+                  "VALUES('sync%q:%q','{}',now())",
+       bSyncFrom ? "from" : "with", x.canonical);
+    db_protect_pop();
+  }
+  url_unparse(&x);
+}
+
+/*
+** If this variable is set, disable login checks.  Used for debugging
+** only.
+*/
+static int disableLogin = 0;
+
+/*
+** Must be passed the version info from pragmas
+** client-version/server-version cards. If the version info is "new
+** enough" then the loginCardMode is ORd into the X-Fossil-Xfer-Login
+** card flag, else this is a no-op.
+*/
+static void xfer_xflc_check(int iRemoteVersion, int iDate, int iTime,
+                            int fLoginCardMode){
+  if( iRemoteVersion>=22700
+      && (iDate > 20250727
+          || (iDate == 20250727 && iTime >= 110500)) ){
+    g.syncInfo.fLoginCardMode |= fLoginCardMode;
+  }
+}
+
+/*
+** The CGI/HTTP preprocessor always redirects requests with a content-type
+** of application/x-fossil or application/x-fossil-debug to this page,
+** regardless of what path was specified in the HTTP header.  This allows
+** clone clients to specify a URL that omits default pathnames, such
+** as "http://fossil-scm.org/" instead of "http://fossil-scm.org/index.cgi".
+**
+** WEBPAGE: xfer  raw-content  loadavg-exempt
+**
+** This is the transfer handler on the server side.  The transfer
+** message has been uncompressed and placed in the g.cgiIn blob.
+** Process this message and form an appropriate reply.
+*/
+void page_xfer(void){
+  int isPull = 0;
+  int isPush = 0;
+  int nErr = 0;
+  Xfer xfer;
+  int deltaFlag = 0;
+  int isClone = 0;
+  int nGimme = 0;
+  int size;
+  char *zNow;
+  int rc;
+  const char *zScript = 0;
+  char *zUuidList = 0;
+  int nUuidList = 0;
+  char **pzUuidList = 0;
+  int *pnUuidList = 0;
+  int uvCatalogSent = 0;
+  int bSendLinks = 0;
+  int nLogin = 0;
+
+  if( fossil_strcmp(PD("REQUEST_METHOD","POST"),"POST") ){
+     fossil_redirect_home();
+  }
+  g.zLogin = "anonymous";
+  login_set_anon_nobody_capabilities();
+  login_check_credentials();
+  if( g.perm.Clone ) g.perm.Read = 1;
+  cgi_check_for_malice();
+  memset(&xfer, 0, sizeof(xfer));
+  blobarray_zero(xfer.aToken, count(xfer.aToken));
+  cgi_set_content_type(g.zContentType);
+  cgi_reset_content();
+  if( db_schema_is_outofdate() ){
+    @ error database\sschema\sis\sout-of-date\son\sthe\sserver.
+    return;
+  }
+  blob_zero(&xfer.err);
+  xfer.pIn = &g.cgiIn;
+  xfer.pOut = cgi_output_blob();
+  xfer.mxSend = db_get_int("max-download", 5000000);
+  xfer.maxTime = db_get_int("max-download-time", 30);
+  if( xfer.maxTime<1 ) xfer.maxTime = 1;
+  xfer.maxTime += time(NULL);
+  g.xferPanic = 1;
+
+  db_begin_write();
+  db_multi_exec(
+     "CREATE TEMP TABLE onremote(rid INTEGER PRIMARY KEY);"
+     "CREATE TEMP TABLE unk(uuid TEXT PRIMARY KEY) WITHOUT ROWID;"
+  );
+  manifest_crosslink_begin();
+  rc = xfer_run_common_script();
+  if( rc==TH_ERROR ){
+    cgi_reset_content();
+    @ error common\sscript\sfailed:\s%F(g.zErrMsg)
+    nErr++;
+  }
+  zScript = xfer_push_code();
+  if( zScript ){ /* NOTE: Are TH1 transfer hooks enabled? */
+    pzUuidList = &zUuidList;
+    pnUuidList = &nUuidList;
+  }
+  if( g.syncInfo.zLoginCard ){
+    /* Login card received via HTTP Cookie header */
+    blob_zero(&xfer.line);
+    blob_append(&xfer.line, g.syncInfo.zLoginCard, -1);
+    xfer.nToken = blob_tokenize(&xfer.line, xfer.aToken,
+                                count(xfer.aToken));
+    fossil_free( g.syncInfo.zLoginCard );
+    g.syncInfo.zLoginCard = 0;
+    if( xfer.nToken==4
+        && blob_eq(&xfer.aToken[0], "login") ){
+      goto handle_login_card;
+    }
+  }
+  while( blob_line(xfer.pIn, &xfer.line) ){
+    if( blob_buffer(&xfer.line)[0]=='#' ) continue;
+    if( blob_size(&xfer.line)==0 ) continue;
+    xfer.nToken = blob_tokenize(&xfer.line, xfer.aToken, count(xfer.aToken));
+
+    /*   file HASH SIZE \n CONTENT
+    **   file HASH DELTASRC SIZE \n CONTENT
+    **
+    ** Server accepts a file from the client.
+    */
+    if( blob_eq(&xfer.aToken[0], "file") ){
+      if( !isPush ){
+        cgi_reset_content();
+        @ error not\sauthorized\sto\swrite%s(whyNotAuth())
+        nErr++;
+        break;
+      }
+      xfer_accept_file(&xfer, 0, pzUuidList, pnUuidList);
+      if( blob_size(&xfer.err) ){
+        cgi_reset_content();
+        @ error %T(blob_str(&xfer.err))
+        nErr++;
+        break;
+      }
+    }else
+
+    /*   cfile HASH USIZE CSIZE \n CONTENT
+    **   cfile HASH DELTASRC USIZE CSIZE \n CONTENT
+    **
+    ** Server accepts a compressed file from the client.
+    */
+    if( blob_eq(&xfer.aToken[0], "cfile") ){
+      if( !isPush ){
+        cgi_reset_content();
+        @ error not\sauthorized\sto\swrite%s(whyNotAuth())
+        nErr++;
+        break;
+      }
+      xfer_accept_compressed_file(&xfer, pzUuidList, pnUuidList);
+      if( blob_size(&xfer.err) ){
+        cgi_reset_content();
+        @ error %T(blob_str(&xfer.err))
+        nErr++;
+        break;
+      }
+    }else
+
+    /*   uvfile NAME MTIME HASH SIZE FLAGS \n CONTENT
+    **
+    ** Server accepts an unversioned file from the client.
+    */
+    if( blob_eq(&xfer.aToken[0], "uvfile") ){
+      xfer_accept_unversioned_file(&xfer, g.perm.WrUnver);
+      if( blob_size(&xfer.err) ){
+        cgi_reset_content();
+        @ error %T(blob_str(&xfer.err))
+        fossil_print("%%%%%%%% xfer.err: '%s'\n", blob_str(&xfer.err));
+        nErr++;
+        break;
+      }
+    }else
+
+    /*   gimme HASH
+    **
+    ** Client is requesting a file from the server.  Send it.
+    */
+    if( blob_eq(&xfer.aToken[0], "gimme")
+     && xfer.nToken==2
+     && blob_is_hname(&xfer.aToken[1])
+    ){
+      nGimme++;
+      remote_unk(&xfer.aToken[1]);
+      if( isPull ){
+        int rid = rid_from_uuid(&xfer.aToken[1], 0, 0);
+        if( rid ){
+          send_file(&xfer, rid, &xfer.aToken[1], deltaFlag);
+        }
+      }
+    }else
+
+    /*   uvgimme NAME
+    **
+    ** Client is requesting an unversioned file from the server.  Send it.
+    */
+    if( blob_eq(&xfer.aToken[0], "uvgimme")
+     && xfer.nToken==2
+     && blob_is_filename(&xfer.aToken[1])
+    ){
+      send_unversioned_file(&xfer, blob_str(&xfer.aToken[1]), 0);
+    }else
+
+    /*   igot HASH ?ISPRIVATE?
+    **
+    ** Client announces that it has a particular file.  If the ISPRIVATE
+    ** argument exists and is "1", then the file is a private file.
+    */
+    if( xfer.nToken>=2
+     && blob_eq(&xfer.aToken[0], "igot")
+     && blob_is_hname(&xfer.aToken[1])
+    ){
+      if( isPush ){
+        int rid = 0;
+        int isPriv = 0;
+        if( xfer.nToken==2 || blob_eq(&xfer.aToken[2],"1")==0 ){
+          /* Client says the artifact is public */
+          rid = rid_from_uuid(&xfer.aToken[1], 1, 0);
+        }else if( g.perm.Private ){
+          /* Client says the artifact is private and the client has
+          ** permission to push private content.  Create a new phantom
+          ** artifact that is marked private. */
+          rid = rid_from_uuid(&xfer.aToken[1], 1, 1);
+          isPriv = 1;
+        }else{
+          /* Client says the artifact is private and the client is unable
+          ** or unwilling to send us the artifact.  If we already hold the
+          ** artifact here on the server as a phantom, make sure that
+          ** phantom is marked as private so that we don't keep asking about
+          ** it in subsequent sync requests. */
+          rid = rid_from_uuid(&xfer.aToken[1], 0, 1);
+          isPriv = 1;
+        }
+        if( rid ){
+          remote_has(rid);
+          if( isPriv ){
+            content_make_private(rid);
+          }else{
+            content_make_public(rid);
+          }
+        }
+      }
+    }else
+
+
+    /*    pull  SERVERCODE  PROJECTCODE
+    **    push  SERVERCODE  PROJECTCODE
+    **
+    ** The client wants either send or receive.  The server should
+    ** verify that the project code matches.  The server code is ignored.
+    */
+    if( xfer.nToken==3
+     && (blob_eq(&xfer.aToken[0], "pull") || blob_eq(&xfer.aToken[0], "push"))
+     && blob_is_hname(&xfer.aToken[2])
+    ){
+      const char *zPCode;
+      zPCode = db_get("project-code", 0);
+      if( zPCode==0 ){
+        fossil_fatal("missing project code");
+      }
+      if( !blob_eq_str(&xfer.aToken[2], zPCode, -1) ){
+        cgi_reset_content();
+        @ error wrong\sproject
+        nErr++;
+        break;
+      }
+      login_check_credentials();
+      if( blob_eq(&xfer.aToken[0], "pull") ){
+        if( !g.perm.Read ){
+          cgi_reset_content();
+          @ error not\sauthorized\sto\sread%s(whyNotAuth())
+          nErr++;
+          break;
+        }
+        isPull = 1;
+      }else{
+        if( !g.perm.Write ){
+          if( !isPull ){
+            cgi_reset_content();
+            @ error not\sauthorized\sto\swrite%s(whyNotAuth())
+            nErr++;
+          }else{
+            @ message pull\sonly\s-\snot\sauthorized\sto\spush%s(whyNotAuth())
+          }
+        }else{
+          isPush = 1;
+        }
+      }
+    }else
+
+    /*    clone   ?PROTOCOL-VERSION?  ?SEQUENCE-NUMBER?
+    **
+    ** The client knows nothing.  Tell all.
+    */
+    if( blob_eq(&xfer.aToken[0], "clone") ){
+      int iVers;
+      login_check_credentials();
+      if( !g.perm.Clone ){
+        cgi_reset_content();
+        @ push %s(db_get("server-code", "x")) %s(db_get("project-code", "x"))
+        @ error not\sauthorized\sto\sclone%s(whyNotAuth())
+        nErr++;
+        break;
+      }
+      if( db_get_boolean("uv-sync",0) && !uvCatalogSent ){
+        @ pragma uv-pull-only
+        send_unversioned_catalog(&xfer);
+        uvCatalogSent = 1;
+      }
+      if( xfer.nToken==3
+       && blob_is_int(&xfer.aToken[1], &iVers)
+       && iVers>=2
+      ){
+        int seqno, max;
+        if( iVers>=3 ){
+          cgi_set_content_type("application/x-fossil-uncompressed");
+        }
+        blob_is_int(&xfer.aToken[2], &seqno);
+        if( seqno<=0 ){
+          xfer_fatal_error("invalid clone sequence number");
+          db_rollback_transaction();
+          return;
+        }
+        max = db_int(0, "SELECT max(rid) FROM blob");
+        while( xfer.mxSend>(int)blob_size(xfer.pOut) && seqno<=max){
+          if( time(NULL) >= xfer.maxTime ) break;
+          if( iVers>=3 ){
+            send_compressed_file(&xfer, seqno);
+          }else{
+            send_file(&xfer, seqno, 0, 1);
+          }
+          seqno++;
+        }
+        if( seqno>max ) seqno = 0;
+        @ clone_seqno %d(seqno)
+      }else{
+        isClone = 1;
+        isPull = 1;
+        deltaFlag = 1;
+      }
+      @ push %s(db_get("server-code", "x")) %s(db_get("project-code", "x"))
+    }else
+
+    /*    login  USER  NONCE  SIGNATURE
+    **
+    ** The client has sent login credentials to the server.
+    ** Validate the login.  This has to happen before anything else.
+    **
+    ** For many years, Fossil would accept multiple login cards with
+    ** cumulative permissions.  But that feature was never used.  Hence
+    ** it is now prohibited.  Any login card after the first generates
+    ** a fatal error.
+    */
+    if( blob_eq(&xfer.aToken[0], "login")
+     && xfer.nToken==4
+    ){
+    handle_login_card:
+      nLogin++;
+      if( disableLogin ){
+        g.perm.Read = g.perm.Write = g.perm.Private = g.perm.Admin = 1;
+      }else if( nLogin > 1 ){
+        cgi_reset_content();
+        @ error multiple\slogin\cards
+        nErr++;
+        break;
+      }else{
+        if( check_tail_hash(&xfer.aToken[2], xfer.pIn)
+         || check_login(&xfer.aToken[1], &xfer.aToken[2], &xfer.aToken[3])
+        ){
+          cgi_reset_content();
+          @ error login\sfailed
+          nErr++;
+          break;
+        }
+      }
+    }else
+
+    /*    reqconfig  NAME
+    **
+    ** Client is requesting a configuration value from the server
+    */
+    if( blob_eq(&xfer.aToken[0], "reqconfig")
+     && xfer.nToken==2
+    ){
+      if( g.perm.Read ){
+        char *zName = blob_str(&xfer.aToken[1]);
+        if( zName[0]=='/' ){
+          /* New style configuration transfer */
+          int groupMask = configure_name_to_mask(&zName[1], 0);
+          if( !g.perm.Admin ) groupMask &= ~(CONFIGSET_USER|CONFIGSET_SCRIBER);
+          if( !g.perm.RdAddr ) groupMask &= ~CONFIGSET_ADDR;
+          configure_send_group(xfer.pOut, groupMask, 0);
+        }
+      }
+    }else
+
+    /*   config NAME SIZE \n CONTENT
+    **
+    ** Client has sent a configuration value to the server.
+    ** This is only permitted for high-privilege users.
+    */
+    if( blob_eq(&xfer.aToken[0],"config") && xfer.nToken==3
+        && blob_is_int(&xfer.aToken[2], &size) ){
+      const char *zName = blob_str(&xfer.aToken[1]);
+      Blob content;
+      if( size<0 ){
+        xfer_fatal_error("invalid config record");
+        db_rollback_transaction();
+        return;
+      }
+      blob_zero(&content);
+      blob_extract(xfer.pIn, size, &content);
+      if( !g.perm.Admin ){
+        cgi_reset_content();
+        @ error not\sauthorized\sto\spush\sconfiguration%s(whyNotAuth())
+        nErr++;
+        break;
+      }
+      configure_receive(zName, &content, CONFIGSET_ALL);
+      blob_reset(&content);
+      blob_seek(xfer.pIn, 1, BLOB_SEEK_CUR);
+    }else
+
+
+    /*    cookie TEXT
+    **
+    ** A cookie contains an arbitrary-length argument that is server-defined.
+    ** The argument must be encoded so as not to contain any whitespace.
+    ** The server can optionally send a cookie to the client.  The client
+    ** might then return the same cookie back to the server on its next
+    ** communication.  The cookie might record information that helps
+    ** the server optimize a push or pull.
+    **
+    ** The client is not required to return a cookie.  So the server
+    ** must not depend on the cookie.  The cookie should be an optimization
+    ** only.  The client might also send a cookie that came from a different
+    ** server.  So the server must be prepared to distinguish its own cookie
+    ** from cookies originating from other servers.  The client might send
+    ** back several different cookies to the server.  The server should be
+    ** prepared to sift through the cookies and pick the one that it wants.
+    */
+    if( blob_eq(&xfer.aToken[0], "cookie") && xfer.nToken==2 ){
+      /* Process the cookie */
+    }else
+
+
+    /*    private
+    **
+    ** The client card indicates that the next "file" or "cfile" will contain
+    ** private content.
+    */
+    if( blob_eq(&xfer.aToken[0], "private") ){
+      if( !g.perm.Private ){
+        server_private_xfer_not_authorized();
+      }else{
+        xfer.nextIsPrivate = 1;
+      }
+    }else
+
+    /*    pragma NAME VALUE...
+    **
+    ** The client issues pragmas to try to influence the behavior of the
+    ** server.  These are requests only.  Unknown pragmas are silently
+    ** ignored.
+    */
+    if( blob_eq(&xfer.aToken[0], "pragma") && xfer.nToken>=2 ){
+
+      /*   pragma send-private
+      **
+      ** The client is requesting private artifacts.
+      **
+      ** If the user has the "x" privilege (which must be set explicitly -
+      ** it is not automatic with "a" or "s") then this pragma causes
+      ** private information to be pulled in addition to public records.
+      */
+      if( blob_eq(&xfer.aToken[1], "send-private") ){
+        login_check_credentials();
+        if( !g.perm.Private ){
+          server_private_xfer_not_authorized();
+        }else{
+          xfer.syncPrivate = 1;
+        }
+      }else
+
+      /*   pragma send-catalog
+      **
+      ** The client wants to see igot cards for all known artifacts.
+      ** This is used as part of "sync --verily" to help ensure that
+      ** no artifacts have been missed on prior syncs.
+      */
+      if( blob_eq(&xfer.aToken[1], "send-catalog") ){
+        xfer.resync = 0x7fffffff;
+      }else
+
+      /*   pragma client-version VERSION ?DATE? ?TIME?
+      **
+      ** The client announces to the server what version of Fossil it
+      ** is running.  The DATE and TIME are a pure numeric ISO8601 time
+      ** for the specific check-in of the client.
+      */
+      if( xfer.nToken>=3 && blob_eq(&xfer.aToken[1], "client-version") ){
+        xfer.remoteVersion = g.syncInfo.remoteVersion =
+          atoi(blob_str(&xfer.aToken[2]));
+        if( xfer.nToken>=5 ){
+          xfer.remoteDate = atoi(blob_str(&xfer.aToken[3]));
+          xfer.remoteTime = atoi(blob_str(&xfer.aToken[4]));
+          @ pragma server-version %d(RELEASE_VERSION_NUMBER) \
+          @ %d(MANIFEST_NUMERIC_DATE) %d(MANIFEST_NUMERIC_TIME)
+        }
+        xfer_xflc_check( xfer.remoteVersion, xfer.remoteDate,
+                         xfer.remoteTime, 0x04 );
+      }else
+
+      /*   pragma uv-hash HASH
+      **
+      ** The client wants to make sure that unversioned files are all synced.
+      ** If the HASH does not match, send a complete catalog of
+      ** "uvigot" cards.
+      */
+      if( blob_eq(&xfer.aToken[1], "uv-hash")
+       && blob_is_hname(&xfer.aToken[2])
+      ){
+        if( !uvCatalogSent
+         && g.perm.Read
+         && !blob_eq_str(&xfer.aToken[2], unversioned_content_hash(0),-1)
+        ){
+          if( g.perm.WrUnver ){
+            @ pragma uv-push-ok
+          }else if( g.perm.Read ){
+            @ pragma uv-pull-only
+          }
+          send_unversioned_catalog(&xfer);
+        }
+        uvCatalogSent = 1;
+      }else
+
+      /*   pragma ci-lock CHECKIN-HASH CLIENT-ID
+      **
+      ** The client wants to make non-branch commit against the check-in
+      ** identified by CHECKIN-HASH.  The server will remember this and
+      ** subsequent ci-lock requests from different clients will generate
+      ** a ci-lock-fail pragma in the reply.
+      */
+      if( blob_eq(&xfer.aToken[1], "ci-lock")
+       && xfer.nToken==4
+       && blob_is_hname(&xfer.aToken[2])
+      ){
+        Stmt q;
+        sqlite3_int64 iNow = time(0);
+        sqlite3_int64 maxAge = db_get_int("lock-timeout",60);
+        int seenFault = 0;
+        db_prepare(&q,
+          "SELECT value->>'login',"
+          "       mtime,"
+          "       value->>'clientid',"
+          "       (SELECT rid FROM blob WHERE uuid=substr(name,9)),"
+          "       name"
+          " FROM config"
+          " WHERE name GLOB 'ci-lock-*'"
+          "   AND json_valid(value)"
+        );
+        while( db_step(&q)==SQLITE_ROW ){
+          int x = db_column_int(&q,3);
+          const char *zName = db_column_text(&q,4);
+          if( db_column_int64(&q,1)<=iNow-maxAge || !is_a_leaf(x) ){
+            /* check-in locks expire after maxAge seconds, or when the
+            ** check-in is no longer a leaf */
+            db_unprotect(PROTECT_CONFIG);
+            db_multi_exec("DELETE FROM config WHERE name=%Q", zName);
+            db_protect_pop();
+            continue;
+          }
+          if( fossil_strcmp(zName+8, blob_str(&xfer.aToken[2]))==0 ){
+            const char *zClientId = db_column_text(&q, 2);
+            const char *zLogin = db_column_text(&q,0);
+            sqlite3_int64 mtime = db_column_int64(&q, 1);
+            if( fossil_strcmp(zClientId, blob_str(&xfer.aToken[3]))!=0 ){
+              @ pragma ci-lock-fail %F(zLogin) %lld(mtime)
+            }
+            seenFault = 1;
+          }
+        }
+        db_finalize(&q);
+        if( !seenFault ){
+          db_unprotect(PROTECT_CONFIG);
+          db_multi_exec(
+            "REPLACE INTO config(name,value,mtime)"
+            "VALUES('ci-lock-%q',json_object('login',%Q,'clientid',%Q),now())",
+            blob_str(&xfer.aToken[2]), g.zLogin,
+            blob_str(&xfer.aToken[3])
+          );
+          db_protect_pop();
+        }
+        if( db_get_boolean("forbid-delta-manifests",0) ){
+          @ pragma avoid-delta-manifests
+        }
+      }else
+
+      /*   pragma ci-unlock CLIENT-ID
+      **
+      ** Remove any locks previously held by CLIENT-ID.  Clients send this
+      ** pragma with their own ID whenever they know that they no longer
+      ** have any commits pending.
+      */
+      if( blob_eq(&xfer.aToken[1], "ci-unlock")
+       && xfer.nToken==3
+       && blob_is_hname(&xfer.aToken[2])
+      ){
+        db_unprotect(PROTECT_CONFIG);
+        db_multi_exec(
+          "DELETE FROM config"
+          " WHERE name GLOB 'ci-lock-*'"
+          "   AND (NOT json_valid(value) OR value->>'clientid'==%Q)",
+          blob_str(&xfer.aToken[2])
+        );
+        db_protect_pop();
+      }else
+
+      /*   pragma client-url URL
+      **
+      ** This pragma is an informational notification to the server that
+      ** their relationship could, in theory, be inverted by having the
+      ** server call the client at URL.
+      */
+      if( blob_eq(&xfer.aToken[1], "client-url")
+       && xfer.nToken==3
+       && g.perm.Write
+      ){
+        xfer_syncwith(blob_str(&xfer.aToken[2]), 1);
+      }else
+
+      /*    pragma req-links
+      **
+      ** The client sends this message to the server to ask the server
+      ** to tell it about alternative repositories  in the reply.
+      */
+      if( blob_eq(&xfer.aToken[1], "req-links") ){
+        bSendLinks = 1;
+      }else
+
+      /*   pragma req-clusters
+      **
+      ** This pragma requests that the server send igot cards for every
+      ** cluster artifact that it knows about.
+      */
+      if( blob_eq(&xfer.aToken[1], "req-clusters") ){
+        send_all_clusters(&xfer);
+      }
+
+    }else
+
+    /* Unknown message
+    */
+    {
+      cgi_reset_content();
+      @ error bad\scommand:\s%F(blob_str(&xfer.line))
+    }
+    blobarray_reset(xfer.aToken, xfer.nToken);
+    blob_reset(&xfer.line);
+  }
+  if( isPush ){
+    if( rc==TH_OK ){
+      rc = xfer_run_script(zScript, zUuidList, 1);
+      if( rc==TH_ERROR ){
+        cgi_reset_content();
+        @ error push\sscript\sfailed:\s%F(g.zErrMsg)
+        nErr++;
+      }
+    }
+    request_phantoms(&xfer, 500);
+  }
+  if( zUuidList ){
+    Th_Free(g.interp, zUuidList);
+  }
+  if( isClone && nGimme==0 ){
+    /* The initial "clone" message from client to server contains no
+    ** "gimme" cards. On that initial message, send the client an "igot"
+    ** card for every artifact currently in the repository.  This will
+    ** cause the client to create phantoms for all artifacts, which will
+    ** in turn make sure that the entire repository is sent efficiently
+    ** and expeditiously.
+    */
+    send_all(&xfer);
+    if( xfer.syncPrivate ) send_private(&xfer);
+  }else if( isPull ){
+    create_cluster();
+    send_unclustered(&xfer);
+    if( xfer.syncPrivate ) send_private(&xfer);
+  }
+  hook_expecting_more_artifacts(xfer.nGimmeSent?60:0);
+  db_multi_exec("DROP TABLE onremote; DROP TABLE unk;");
+  manifest_crosslink_end(MC_PERMIT_HOOKS);
+
+  /* Send URLs for alternative repositories for the same project,
+  ** if requested by the client. */
+  if( bSendLinks && g.zBaseURL ){
+    Stmt q;
+    db_prepare(&q,
+      "WITH remote(mtime, url, arg) AS (\n"
+      "  SELECT mtime, substr(name,10), '{}' FROM config\n"
+      "   WHERE name GLOB 'syncwith:http*'\n"
+      "  UNION ALL\n"
+      "  SELECT mtime, substr(name,10), '{}' FROM config\n"
+      "   WHERE name GLOB 'syncfrom:http*'\n"
+      "  UNION ALL\n"
+      "  SELECT mtime, substr(name,9), '{\"type\":\"git\"}' FROM config\n"
+      "   WHERE name GLOB 'gitpush:*'\n"
+      ")\n"
+      "SELECT url, json_insert(arg,'$.src',%Q), max(mtime)\n"
+      "  FROM remote WHERE mtime>unixepoch('now','-1 month')\n"
+      " GROUP BY url;",
+      g.zBaseURL
+    );
+    while( db_step(&q)==SQLITE_ROW ){
+      UrlData x;
+      const char *zUrl = db_column_text(&q, 0);
+      const char *zArg = db_column_text(&q, 1);
+      i64 iMtime = db_column_int64(&q, 2);
+      memset(&x, 0, sizeof(x));
+      url_parse_local(zUrl, URL_OMIT_USER, &x);
+      if( x.name!=0 && sqlite3_strlike("%localhost%", x.name, 0)!=0 ){
+        @ pragma link %F(x.canonical) %F(zArg) %lld(iMtime)
+      }
+      url_unparse(&x);
+    }
+    db_finalize(&q);
+  }
+
+  /* Send the server timestamp last, in case prior processing happened
+  ** to use up a significant fraction of our time window.
+  */
+  zNow = db_text(0, "SELECT strftime('%%Y-%%m-%%dT%%H:%%M:%%S', 'now')");
+  @ # timestamp %s(zNow) errors %d(nErr)
+  fossil_free(zNow);
+
+  db_commit_transaction();
+  configure_rebuild();
+}
+
+/*
+** COMMAND: test-xfer
+**
+** Usage: %fossil test-xfer ?OPTIONS? XFERFILE
+**
+** Pass the sync-protocol input file XFERFILE into the server-side sync
+** protocol handler.  Generate a reply on standard output.
+**
+** This command was original created to help debug the server side of
+** sync messages.  The XFERFILE is the uncompressed content of an
+** "xfer" HTTP request from client to server.  This command interprets
+** that message and generates the content of an HTTP reply (without any
+** encoding and without the HTTP reply headers) and writes that reply
+** on standard output.
+**
+** One possible usages scenario is to capture some XFERFILE examples
+** using a command like:
+**
+**     fossil push http://bogus/ --httptrace
+**
+** The complete HTTP requests are stored in files named "http-request-N.txt".
+** Find one of those requests, remove the HTTP header, and make other edits
+** as necessary to generate an appropriate XFERFILE test case.  Then run:
+**
+**     fossil test-xfer xferfile.txt
+**
+** Options:
+**    --host  HOSTNAME             Supply a server hostname used to populate
+**                                 g.zBaseURL and similar.
+*/
+void cmd_test_xfer(void){
+  const char *zHost;
+  db_find_and_open_repository(0,0);
+  zHost = find_option("host",0,1);
+  verify_all_options();
+  if( g.argc!=2 && g.argc!=3 ){
+    usage("?MESSAGEFILE?");
+  }
+  if( zHost==0 ) zHost = "localhost:8080";
+  g.zBaseURL = mprintf("http://%s", zHost);
+  g.zHttpsURL = mprintf("https://%s", zHost);
+  g.zTop = mprintf("");
+  blob_zero(&g.cgiIn);
+  blob_read_from_file(&g.cgiIn, g.argc==2 ? "-" : g.argv[2], ExtFILE);
+  disableLogin = 1;
+  page_xfer();
+  fossil_print("%s", cgi_extract_content());
+}
+
+/*
+** Format strings for progress reporting.
+*/
+static const char zLabelFormat[] = "%-10s %10s %10s %10s %10s\n";
+static const char zValueFormat[] = "\r%-10s %10d %10d %10d %10d\n";
+static const char zBriefFormat[] =
+   "Round-trips: %d   Artifacts sent: %d  received: %d\r";
+
+#if INTERFACE
+/*
+** Flag options for controlling client_sync()
+*/
+#define SYNC_PUSH           0x00001    /* push content client to server */
+#define SYNC_PULL           0x00002    /* pull content server to client */
+#define SYNC_CLONE          0x00004    /* clone the repository */
+#define SYNC_PRIVATE        0x00008    /* Also transfer private content */
+#define SYNC_VERBOSE        0x00010    /* Extra diagnostics */
+#define SYNC_RESYNC         0x00020    /* --verily */
+#define SYNC_FROMPARENT     0x00040    /* Pull from the parent project */
+#define SYNC_UNVERSIONED    0x00100    /* Sync unversioned content */
+#define SYNC_UV_REVERT      0x00200    /* Copy server unversioned to client */
+#define SYNC_UV_TRACE       0x00400    /* Describe UV activities */
+#define SYNC_UV_DRYRUN      0x00800    /* Do not actually exchange files */
+#define SYNC_IFABLE         0x01000    /* Inability to sync is not fatal */
+#define SYNC_CKIN_LOCK      0x02000    /* Lock the current check-in */
+#define SYNC_NOHTTPCOMPRESS 0x04000    /* Do not compression HTTP messages */
+#define SYNC_ALLURL         0x08000    /* The --all flag - sync to all URLs */
+#define SYNC_SHARE_LINKS    0x10000    /* Request alternate repo links */
+#define SYNC_XVERBOSE       0x20000    /* Extra verbose.  Network traffic */
+#define SYNC_PING           0x40000    /* Verify server is alive */
+#define SYNC_QUIET          0x80000    /* No output */
+#endif
+
+/*
+** Floating-point absolute value
+*/
+static double fossil_fabs(double x){
+  return x>0.0 ? x : -x;
+}
+
+/*
+** Sync to the host identified in g.url.name and g.url.path.  This
+** routine is called by the client.
+**
+** Records are pushed to the server if pushFlag is true.  Records
+** are pulled if pullFlag is true.  A full sync occurs if both are
+** true.
+*/
+int client_sync(
+  unsigned syncFlags,      /* Mask of SYNC_* flags */
+  unsigned configRcvMask,  /* Receive these configuration items */
+  unsigned configSendMask, /* Send these configuration items */
+  const char *zAltPCode,   /* Alternative project code (usually NULL) */
+  int *pnRcvd              /* Set to # received artifacts, if not NULL */
+){
+  int go = 1;             /* Loop until zero */
+  int nCardSent = 0;      /* Number of cards sent */
+  int nCardRcvd = 0;      /* Number of cards received */
+  int nCycle = 0;         /* Number of round trips to the server */
+  int size;               /* Size of a config value or uvfile */
+  int origConfigRcvMask;  /* Original value of configRcvMask */
+  int nFileRecv = 0;      /* Number of files received */
+  int mxPhantomReq = 200; /* Max number of phantoms to request per comm */
+  const char *zCookie;    /* Server cookie */
+  i64 nUncSent, nUncRcvd; /* Bytes sent and received (before compression) */
+  i64 nSent, nRcvd;       /* Bytes sent and received (after compression) */
+  int cloneSeqno = 1;     /* Sequence number for clones */
+  Blob send;              /* Text we are sending to the server */
+  Blob recv;              /* Reply we got back from the server */
+  Xfer xfer;              /* Transfer data */
+  int pctDone;            /* Percentage done with a message */
+  int lastPctDone = -1;   /* Last displayed pctDone */
+  double rArrivalTime;    /* Time at which a message arrived */
+  const char *zSCode = db_get("server-code", "x");
+  const char *zPCode = db_get("project-code", 0);
+  int nErr = 0;           /* Number of errors */
+  int nRoundtrip= 0;      /* Number of HTTP requests */
+  int nArtifactSent = 0;  /* Total artifacts sent */
+  int nArtifactRcvd = 0;  /* Total artifacts received */
+  int nPriorArtifact = 0; /* Artifacts received on prior round-trips */
+  const char *zOpType = 0;/* Push, Pull, Sync, Clone */
+  double rSkew = 0.0;     /* Maximum time skew */
+  int uvHashSent = 0;     /* The "pragma uv-hash" message has been sent */
+  int uvDoPush = 0;       /* Generate uvfile messages to send to server */
+  int uvPullOnly = 0;     /* 1: pull-only.  2: pull-only warning issued */
+  int nUvGimmeSent = 0;   /* Number of uvgimme cards sent on this cycle */
+  int nUvFileRcvd = 0;    /* Number of uvfile cards received on this cycle */
+  int nGimmeRcvd = 0;     /* Number of gimme cards recevied on the prev cycle */
+  sqlite3_int64 mtime;    /* Modification time on a UV file */
+  int autopushFailed = 0; /* Autopush following commit failed if true */
+  const char *zCkinLock;  /* Name of check-in to lock.  NULL for none */
+  const char *zClientId;  /* A unique identifier for this check-out */
+  unsigned int mHttpFlags;/* Flags for the http_exchange() subsystem */
+  const int bOutIsTty = fossil_isatty(fossil_fileno(stdout));
+
+  if( pnRcvd ) *pnRcvd = 0;
+  if( db_get_boolean("dont-push", 0) ) syncFlags &= ~SYNC_PUSH;
+  if( (syncFlags & (SYNC_PUSH|SYNC_PULL|SYNC_CLONE|SYNC_UNVERSIONED|SYNC_PING))
+            ==0
+     && configRcvMask==0
+     && configSendMask==0
+  ){
+    return 0;  /* Nothing to do */
+  }
+
+  /* Compute an appropriate project code.  zPCode is the project code
+  ** for the local repository.  zAltPCode will usually be NULL, but might
+  ** also be an alternative project code to expect on the server.  When
+  ** zAltPCode is not NULL, that means we are doing a cross-project import -
+  ** in other words, reading content from one project into a different
+  ** project.
+  */
+  if( syncFlags & SYNC_FROMPARENT ){
+    const char *zPX;
+    configRcvMask = 0;
+    configSendMask = 0;
+    syncFlags &= ~(SYNC_PUSH);
+    zPX = db_get("parent-project-code", 0);
+    if( zPX==0 || db_get("parent-project-name",0)==0 ){
+      fossil_fatal("there is no parent project: set the 'parent-project-code'"
+                   " and 'parent-project-name' config parameters in order"
+                   " to pull from a parent project");
+    }
+    if( zPX ){
+      zAltPCode = zPX;
+    }
+  }
+  if( zAltPCode!=0 && zPCode!=0 && sqlite3_stricmp(zPCode, zAltPCode)==0 ){
+    zAltPCode = 0;
+  }
+
+  transport_stats(0, 0, 1);
+  socket_global_init();
+  memset(&xfer, 0, sizeof(xfer));
+  xfer.pIn = &recv;
+  xfer.pOut = &send;
+  xfer.mxSend = db_get_int("max-upload", 250000);
+  xfer.maxTime = -1;
+  xfer.remoteVersion = RELEASE_VERSION_NUMBER;
+  if( syncFlags & SYNC_PRIVATE ){
+    g.perm.Private = 1;
+    xfer.syncPrivate = 1;
+  }
+
+  blobarray_zero(xfer.aToken, count(xfer.aToken));
+  blob_zero(&send);
+  blob_zero(&recv);
+  blob_zero(&xfer.err);
+  blob_zero(&xfer.line);
+  origConfigRcvMask = 0;
+  nUncSent = nUncRcvd = 0;
+
+  /* Send the send-private pragma if we are trying to sync private data */
+  if( syncFlags & SYNC_PRIVATE ){
+    blob_append(&send, "pragma send-private\n", -1);
+  }
+
+  /* Figure out which check-in to lock */
+  if( syncFlags & SYNC_CKIN_LOCK ){
+    int vid = db_lget_int("checkout",0);
+    zCkinLock = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", vid);
+  }else{
+    zCkinLock = 0;
+  }
+  zClientId = g.localOpen ? db_lget("client-id", 0) : 0;
+
+  /* When syncing unversioned files, create a TEMP table in which to store
+  ** the names of files that need to be sent from client to server.
+  **
+  ** The initial assumption is that all unversioned files need to be sent
+  ** to the other side.  But "uvigot" cards received back from the remote
+  ** side will normally cause many of these entries to be removed since they
+  ** do not really need to be sent.
+  */
+  if( (syncFlags & (SYNC_UNVERSIONED|SYNC_CLONE))!=0 ){
+    unversioned_schema();
+    db_multi_exec(
+       "CREATE TEMP TABLE IF NOT EXISTS uv_tosend("
+       "  name TEXT PRIMARY KEY,"  /* Name of file to send client->server */
+       "  mtimeOnly BOOLEAN"       /* True to only send mtime, not content */
+       ") WITHOUT ROWID;"
+       "REPLACE INTO uv_tosend(name,mtimeOnly)"
+       "  SELECT name, 0 FROM unversioned WHERE hash IS NOT NULL;"
+    );
+  }
+
+  /*
+  ** The request from the client always begin with a clone, pull,
+  ** or push message.
+  */
+  blob_appendf(&send, "pragma client-version %d %d %d\n",
+               RELEASE_VERSION_NUMBER, MANIFEST_NUMERIC_DATE,
+               MANIFEST_NUMERIC_TIME);
+  if( syncFlags & SYNC_CLONE ){
+    blob_appendf(&send, "clone 3 %d\n", cloneSeqno);
+    syncFlags &= ~(SYNC_PUSH|SYNC_PULL);
+    nCardSent++;
+    /* TBD: Request all transferable configuration values */
+    content_enable_dephantomize(0);
+    zOpType = "Clone";
+  }else if( syncFlags & SYNC_PULL ){
+    blob_appendf(&send, "pull %s %s\n", zSCode,
+                 zAltPCode ? zAltPCode : zPCode);
+    nCardSent++;
+    zOpType = (syncFlags & SYNC_PUSH)?"Sync":"Pull";
+    if( (syncFlags & SYNC_RESYNC)!=0 && nCycle<2 ){
+      blob_appendf(&send, "pragma send-catalog\n");
+      nCardSent++;
+    }
+  }
+  if( syncFlags & SYNC_PUSH ){
+    blob_appendf(&send, "push %s %s\n", zSCode, zPCode);
+    nCardSent++;
+    if( (syncFlags & SYNC_PULL)==0 ) zOpType = "Push";
+    if( (syncFlags & SYNC_RESYNC)!=0 ) xfer.resync = 0x7fffffff;
+  }
+  if( syncFlags & SYNC_VERBOSE ){
+    fossil_print(zLabelFormat /*works-like:"%s%s%s%s%d"*/,
+                 "", "Bytes", "Cards", "Artifacts", "Deltas");
+  }
+
+  /* Send the client-url pragma on the first cycle if the client has
+  ** a known public url.
+  */
+  if( zAltPCode==0 ){
+    const char *zSelfUrl = public_url();
+    if( zSelfUrl ){
+      blob_appendf(&send, "pragma client-url %s\n", zSelfUrl);
+    }
+  }
+
+  /* Request URLs of alternative repositories
+  */
+  if( zAltPCode==0 && (syncFlags & SYNC_SHARE_LINKS)!=0 ){
+    blob_appendf(&send, "pragma req-links\n");
+  }
+
+  while( go ){
+    int newPhantom = 0;
+    char *zRandomness;
+    db_begin_transaction();
+    db_record_repository_filename(0);
+    db_multi_exec(
+      "CREATE TEMP TABLE onremote(rid INTEGER PRIMARY KEY);"
+      "CREATE TEMP TABLE unk(uuid TEXT PRIMARY KEY) WITHOUT ROWID;"
+    );
+    manifest_crosslink_begin();
+
+
+    /* Client sends the most recently received cookie back to the server.
+    ** Let the server figure out if this is a cookie that it cares about.
+    */
+    zCookie = db_get("cookie", 0);
+    if( zCookie ){
+      blob_appendf(&send, "cookie %s\n", zCookie);
+    }
+
+    /* Client sends gimme cards for phantoms
+    */
+    if( (syncFlags & SYNC_PULL)!=0
+     || ((syncFlags & SYNC_CLONE)!=0 && cloneSeqno==1)
+    ){
+      request_phantoms(&xfer, mxPhantomReq);
+      if( xfer.nGimmeSent>0 && nCycle==2 && (syncFlags & SYNC_PULL)!=0 ){
+        blob_appendf(&send, "pragma req-clusters\n");
+      }
+    }
+    if( syncFlags & SYNC_PUSH ){
+      send_unsent(&xfer);
+      nCardSent += send_unclustered(&xfer);
+      if( syncFlags & SYNC_PRIVATE ) send_private(&xfer);
+      if( nGimmeRcvd>0 && nCycle==2 ){
+        send_all_clusters(&xfer);
+      }
+    }
+
+    /* Client sends configuration parameter requests.  On a clone, delay sending
+    ** this until the second cycle since the login card might fail on
+    ** the first cycle.
+    */
+    if( configRcvMask && ((syncFlags & SYNC_CLONE)==0 || nCycle>0) ){
+      const char *zName;
+      if( zOpType==0 ) zOpType = "Pull";
+      zName = configure_first_name(configRcvMask);
+      while( zName ){
+        blob_appendf(&send, "reqconfig %s\n", zName);
+        zName = configure_next_name(configRcvMask);
+        nCardSent++;
+      }
+      origConfigRcvMask = configRcvMask;
+      configRcvMask = 0;
+    }
+
+    /* Client sends a request to sync unversioned files.
+    ** On a clone, delay sending this until the second cycle since
+    ** the login card might fail on the first cycle.
+    */
+    if( (syncFlags & SYNC_UNVERSIONED)!=0
+     && ((syncFlags & SYNC_CLONE)==0 || nCycle>0)
+     && !uvHashSent
+    ){
+      blob_appendf(&send, "pragma uv-hash %s\n", unversioned_content_hash(0));
+      nCardSent++;
+      uvHashSent = 1;
+    }
+
+    /* On a "fossil config push", the client send configuration parameters
+    ** being pushed up to the server */
+    if( configSendMask ){
+      if( zOpType==0 ) zOpType = "Push";
+      nCardSent += configure_send_group(xfer.pOut, configSendMask, 0);
+      configSendMask = 0;
+    }
+
+    /* Send unversioned files present here on the client but missing or
+    ** obsolete on the server.
+    **
+    ** Or, if the SYNC_UV_REVERT flag is set, delete the local unversioned
+    ** files that do not exist on the server.
+    **
+    ** This happens on the second exchange, since we do not know what files
+    ** need to be sent until after the uvigot cards from the first exchange
+    ** have been processed.
+    */
+    if( uvDoPush ){
+      assert( (syncFlags & SYNC_UNVERSIONED)!=0 );
+      if( syncFlags & SYNC_UV_DRYRUN ){
+        uvDoPush = 0;
+      }else if( syncFlags & SYNC_UV_REVERT ){
+        db_multi_exec(
+          "DELETE FROM unversioned"
+          " WHERE name IN (SELECT name FROM uv_tosend);"
+          "DELETE FROM uv_tosend;"
+        );
+        uvDoPush = 0;
+      }else{
+        Stmt uvq;
+        int rc = SQLITE_OK;
+        db_prepare(&uvq, "SELECT name, mtimeOnly FROM uv_tosend");
+        while( (rc = db_step(&uvq))==SQLITE_ROW ){
+          const char *zName = db_column_text(&uvq, 0);
+          send_unversioned_file(&xfer, zName, db_column_int(&uvq,1));
+          nCardSent++;
+          nArtifactSent++;
+          db_multi_exec("DELETE FROM uv_tosend WHERE name=%Q", zName);
+          if( syncFlags & SYNC_VERBOSE ){
+            fossil_print("\rUnversioned-file sent: %s\n", zName);
+          }
+          if( (int)blob_size(xfer.pOut)>xfer.mxSend ) break;
+        }
+        db_finalize(&uvq);
+        if( rc==SQLITE_DONE ) uvDoPush = 0;
+      }
+    }
+
+    /* Lock the current check-out */
+    if( zCkinLock ){
+      if( zClientId==0 ){
+        zClientId = db_text(0, "SELECT lower(hex(randomblob(20)))");
+        db_lset("client-id", zClientId);
+      }
+      blob_appendf(&send, "pragma ci-lock %s %s\n", zCkinLock, zClientId);
+      zCkinLock = 0;
+    }else if( zClientId ){
+      blob_appendf(&send, "pragma ci-unlock %s\n", zClientId);
+    }
+    /* Append randomness to the end of the uplink message.  This makes all
+    ** messages unique so that the login-card nonce will always
+    ** be unique.
+    */
+    zRandomness = db_text(0, "SELECT hex(randomblob(20))");
+    blob_appendf(&send, "# %s\n", zRandomness);
+    fossil_free(zRandomness);
+
+    if( (syncFlags & SYNC_VERBOSE)!=0
+     && (syncFlags & SYNC_XVERBOSE)==0
+    ){
+      fossil_print("waiting for server...");
+    }
+    fflush(stdout);
+    /* Exchange messages with the server */
+    if( (syncFlags & SYNC_CLONE)!=0 && nCycle==0 ){
+      /* Do not send a login card on the first round-trip of a clone */
+      mHttpFlags = 0;
+    }else{
+      mHttpFlags = HTTP_USE_LOGIN;
+    }
+    if( syncFlags & SYNC_NOHTTPCOMPRESS ){
+      mHttpFlags |= HTTP_NOCOMPRESS;
+    }
+    if( syncFlags & SYNC_XVERBOSE ){
+      mHttpFlags |= HTTP_VERBOSE;
+    }
+    if( syncFlags & SYNC_QUIET ){
+      mHttpFlags |= HTTP_QUIET;
+    }
+
+    /* Do the round-trip to the server */
+    if( http_exchange(&send, &recv, mHttpFlags, MAX_REDIRECTS, 0) ){
+      nErr++;
+      go = 2;
+      break;
+    }
+
+    /* Remember the URL of the sync target in the config file on the
+    ** first successful round-trip */
+    if( nCycle==0 && db_is_writeable("repository") ){
+      xfer_syncwith(g.url.canonical, 0);
+    }
+
+    /* Output current stats */
+    nRoundtrip++;
+    nArtifactSent += xfer.nFileSent + xfer.nDeltaSent;
+    if( syncFlags & SYNC_VERBOSE ){
+      fossil_print(zValueFormat /*works-like:"%s%d%d%d%d"*/, "Sent:",
+                   blob_size(&send), nCardSent+xfer.nGimmeSent+xfer.nIGotSent,
+                   xfer.nFileSent, xfer.nDeltaSent);
+    }else if( syncFlags & SYNC_QUIET ){
+      /* No-op */
+    }else{
+      if( bOutIsTty!=0 ){
+        fossil_print(zBriefFormat /*works-like:"%d%d%d"*/,
+                     nRoundtrip, nArtifactSent, nArtifactRcvd);
+      }
+    }
+    nCardSent = 0;
+    nCardRcvd = 0;
+    xfer.nFileSent = 0;
+    xfer.nDeltaSent = 0;
+    xfer.nGimmeSent = 0;
+    xfer.nIGotSent = 0;
+    xfer.nPrivIGot = 0;
+
+    lastPctDone = -1;
+    nUncSent += blob_size(&send);
+    blob_reset(&send);
+    blob_appendf(&send, "pragma client-version %d %d %d\n",
+                 RELEASE_VERSION_NUMBER, MANIFEST_NUMERIC_DATE,
+                 MANIFEST_NUMERIC_TIME);
+    rArrivalTime = db_double(0.0, "SELECT julianday('now')");
+
+    /* Send the send-private pragma if we are trying to sync private data */
+    if( syncFlags & SYNC_PRIVATE ){
+      blob_append(&send, "pragma send-private\n", -1);
+    }
+
+    /* Begin constructing the next message (which might never be
+    ** sent) by beginning with the pull or push cards
+    */
+    if( syncFlags & SYNC_PULL ){
+      blob_appendf(&send, "pull %s %s\n", zSCode,
+                   zAltPCode ? zAltPCode : zPCode);
+      nCardSent++;
+    }
+    if( syncFlags & SYNC_PUSH ){
+      blob_appendf(&send, "push %s %s\n", zSCode, zPCode);
+      nCardSent++;
+    }
+    go = 0;
+    nUvGimmeSent = 0;
+    nUvFileRcvd = 0;
+    nGimmeRcvd = 0;
+    nPriorArtifact = nArtifactRcvd;
+
+    /* Process the reply that came back from the server */
+    while( blob_line(&recv, &xfer.line) ){
+      if( blob_buffer(&xfer.line)[0]=='#' ){
+        const char *zLine = blob_buffer(&xfer.line);
+        if( memcmp(zLine, "# timestamp ", 12)==0 ){
+          char zTime[20];
+          double rDiff;
+          sqlite3_snprintf(sizeof(zTime), zTime, "%.19s", &zLine[12]);
+          rDiff = db_double(9e99, "SELECT julianday('%q') - %.17g",
+                            zTime, rArrivalTime);
+          if( rDiff>9e98 || rDiff<-9e98 ) rDiff = 0.0;
+          if( rDiff*24.0*3600.0 >= -(blob_size(&recv)/5000.0 + 20) ){
+            rDiff = 0.0;
+          }
+          if( fossil_fabs(rDiff)>fossil_fabs(rSkew) ) rSkew = rDiff;
+        }
+        nCardRcvd++;
+        continue;
+      }
+      xfer.nToken = blob_tokenize(&xfer.line, xfer.aToken, count(xfer.aToken));
+      nCardRcvd++;
+      if( (syncFlags & SYNC_VERBOSE)!=0 && recv.nUsed>0 ){
+        pctDone = (recv.iCursor*100)/recv.nUsed;
+        if( pctDone!=lastPctDone ){
+          fossil_print("\rprocessed: %d%%         ", pctDone);
+          lastPctDone = pctDone;
+          fflush(stdout);
+        }
+      }
+
+      /*   file HASH SIZE \n CONTENT
+      **   file HASH DELTASRC SIZE \n CONTENT
+      **
+      ** Client receives a file transmitted from the server.
+      */
+      if( blob_eq(&xfer.aToken[0],"file") ){
+        xfer_accept_file(&xfer, (syncFlags & SYNC_CLONE)!=0, 0, 0);
+        nArtifactRcvd++;
+      }else
+
+      /*   cfile HASH USIZE CSIZE \n CONTENT
+      **   cfile HASH DELTASRC USIZE CSIZE \n CONTENT
+      **
+      ** Client receives a compressed file transmitted from the server.
+      */
+      if( blob_eq(&xfer.aToken[0],"cfile") ){
+        xfer_accept_compressed_file(&xfer, 0, 0);
+        nArtifactRcvd++;
+      }else
+
+      /*   uvfile NAME MTIME HASH SIZE FLAGS \n CONTENT
+      **
+      ** Client accepts an unversioned file from the server.
+      */
+      if( blob_eq(&xfer.aToken[0], "uvfile") ){
+        xfer_accept_unversioned_file(&xfer, 1);
+        nArtifactRcvd++;
+        nUvFileRcvd++;
+        if( syncFlags & SYNC_VERBOSE ){
+          fossil_print("\rUnversioned-file received: %s\n",
+                       blob_str(&xfer.aToken[1]));
+        }
+      }else
+
+      /*   gimme HASH
+      **
+      ** Client receives an artifact request from the server.
+      ** If the file is a manifest, assume that the server will also want
+      ** to know all of the content artifacts associated with the manifest
+      ** and send those too.
+      */
+      if( blob_eq(&xfer.aToken[0], "gimme")
+       && xfer.nToken==2
+       && blob_is_hname(&xfer.aToken[1])
+      ){
+        remote_unk(&xfer.aToken[1]);
+        if( syncFlags & SYNC_PUSH ){
+          int rid = rid_from_uuid(&xfer.aToken[1], 0, 0);
+          if( rid ){
+            send_file(&xfer, rid, &xfer.aToken[1], 0);
+            nGimmeRcvd++;
+          }
+        }
+      }else
+
+      /*   igot HASH  ?PRIVATEFLAG?
+      **
+      ** Server announces that it has a particular file.  If this is
+      ** not a file that we have and we are pulling, then create a
+      ** phantom to cause this file to be requested on the next cycle.
+      ** Always remember that the server has this file so that we do
+      ** not transmit it by accident.
+      **
+      ** If the PRIVATE argument exists and is 1, then the file is
+      ** private.  Pretend it does not exists if we are not pulling
+      ** private files.
+      */
+      if( xfer.nToken>=2
+       && blob_eq(&xfer.aToken[0], "igot")
+       && blob_is_hname(&xfer.aToken[1])
+      ){
+        int rid;
+        int isPriv = xfer.nToken>=3 && blob_eq(&xfer.aToken[2],"1");
+        rid = rid_from_uuid(&xfer.aToken[1], 0, 0);
+        if( rid>0 ){
+          if( isPriv ){
+            content_make_private(rid);
+          }else{
+            content_make_public(rid);
+          }
+        }else if( isPriv && !g.perm.Private ){
+          /* ignore private files */
+        }else if( (syncFlags & (SYNC_PULL|SYNC_CLONE))!=0 ){
+          rid = content_new(blob_str(&xfer.aToken[1]), isPriv);
+          if( rid ) newPhantom = 1;
+        }
+        remote_has(rid);
+      }else
+
+      /*   uvigot NAME MTIME HASH SIZE
+      **
+      ** Server announces that it has a particular unversioned file.  The
+      ** server will only send this card if the client had previously sent
+      ** a "pragma uv-hash" card with a hash that does not match.
+      **
+      ** If the identified file needs to be transferred, then setup for the
+      ** transfer.  Generate a "uvgimme" card in the reply if the server
+      ** version is newer than the client.  Generate a "uvfile" card if
+      ** the client version is newer than the server.  If HASH is "-"
+      ** (indicating that the file has been deleted) and MTIME is newer,
+      ** then do the deletion.
+      */
+      if( xfer.nToken==5
+       && blob_eq(&xfer.aToken[0], "uvigot")
+       && blob_is_filename(&xfer.aToken[1])
+       && blob_is_int64(&xfer.aToken[2], &mtime)
+       && blob_is_int(&xfer.aToken[4], &size)
+       && (blob_eq(&xfer.aToken[3],"-") || blob_is_hname(&xfer.aToken[3]))
+      ){
+        const char *zName = blob_str(&xfer.aToken[1]);
+        const char *zHash = blob_str(&xfer.aToken[3]);
+        int iStatus;
+        if( mtime<0 || size<0 ){
+          xfer_fatal_error("invalid uvigot");
+          return ++nErr;
+        }
+        iStatus = unversioned_status(zName, mtime, zHash);
+        if( (syncFlags & SYNC_UV_REVERT)!=0 ){
+          if( iStatus==4 ) iStatus = 2;
+          if( iStatus==5 ) iStatus = 1;
+        }
+        if( syncFlags & (SYNC_UV_TRACE|SYNC_UV_DRYRUN) ){
+          const char *zMsg = 0;
+          switch( iStatus ){
+            case 0:
+            case 1: zMsg = "UV-PULL";             break;
+            case 2: zMsg = "UV-PULL-MTIME-ONLY";  break;
+            case 4: zMsg = "UV-PUSH-MTIME-ONLY";  break;
+            case 5: zMsg = "UV-PUSH";             break;
+          }
+          if( zMsg ) fossil_print("\r%s: %s\n", zMsg, zName);
+          if( syncFlags & SYNC_UV_DRYRUN ){
+            iStatus = 99;  /* Prevent any changes or reply messages */
+          }
+        }
+        if( iStatus<=1 ){
+          if( zHash[0]!='-' ){
+            blob_appendf(xfer.pOut, "uvgimme %s\n", zName);
+            nCardSent++;
+            nUvGimmeSent++;
+            db_multi_exec("DELETE FROM unversioned WHERE name=%Q", zName);
+          }else if( iStatus==1 ){
+            db_multi_exec(
+               "UPDATE unversioned"
+               "   SET mtime=%lld, hash=NULL, sz=0, encoding=0, content=NULL"
+               " WHERE name=%Q", mtime, zName
+            );
+            db_unset("uv-hash", 0);
+          }
+        }else if( iStatus==2 ){
+          db_multi_exec(
+            "UPDATE unversioned SET mtime=%lld WHERE name=%Q", mtime, zName
+          );
+          db_unset("uv-hash", 0);
+        }
+        if( iStatus>=4 && uvPullOnly==1 ){
+          fossil_warning(
+            "Warning: uv-pull-only                                       \n"
+            "         Unable to push unversioned content because you lack\n"
+            "         sufficient permission on the server\n"
+          );
+          uvPullOnly = 2;
+        }
+        if( iStatus<=3 || uvPullOnly ){
+          db_multi_exec("DELETE FROM uv_tosend WHERE name=%Q", zName);
+        }else if( iStatus==4 ){
+          db_multi_exec("UPDATE uv_tosend SET mtimeOnly=1 WHERE name=%Q",zName);
+        }else if( iStatus==5 ){
+          db_multi_exec("REPLACE INTO uv_tosend(name,mtimeOnly) VALUES(%Q,0)",
+                        zName);
+        }
+      }else
+
+      /*   push  SERVERCODE  PRODUCTCODE
+      **
+      ** Should only happen in response to a clone.  This message tells
+      ** the client what product code to use for the new database.
+      */
+      if( blob_eq(&xfer.aToken[0],"push")
+       && xfer.nToken==3
+       && (syncFlags & SYNC_CLONE)!=0
+       && blob_is_hname(&xfer.aToken[2])
+      ){
+        if( zPCode==0 ){
+          zPCode = mprintf("%b", &xfer.aToken[2]);
+          db_set("project-code", zPCode, 0);
+        }
+        if( cloneSeqno>0 ) blob_appendf(&send, "clone 3 %d\n", cloneSeqno);
+        nCardSent++;
+      }else
+
+      /*   config NAME SIZE \n CONTENT
+      **
+      ** Client receive a configuration value from the server.
+      **
+      ** The received configuration setting is silently ignored if it was
+      ** not requested by a prior "reqconfig" sent from client to server.
+      */
+      if( blob_eq(&xfer.aToken[0],"config") && xfer.nToken==3
+          && blob_is_int(&xfer.aToken[2], &size) ){
+        const char *zName = blob_str(&xfer.aToken[1]);
+        Blob content;
+        if( size<0 ){
+          xfer_fatal_error("invalid config record");
+          return ++nErr;
+        }
+        blob_zero(&content);
+        blob_extract(xfer.pIn, size, &content);
+        g.perm.Admin = g.perm.RdAddr = 1;
+        configure_receive(zName, &content, origConfigRcvMask);
+        nCardRcvd++;
+        nArtifactRcvd++;
+        blob_reset(&content);
+        blob_seek(xfer.pIn, 1, BLOB_SEEK_CUR);
+      }else
+
+
+      /*    cookie TEXT
+      **
+      ** The client reserves a cookie from the server.  The client
+      ** should remember this cookie and send it back to the server
+      ** in its next query.
+      **
+      ** Each cookie received overwrites the prior cookie from the
+      ** same server.
+      */
+      if( blob_eq(&xfer.aToken[0], "cookie") && xfer.nToken==2 ){
+        db_set("cookie", blob_str(&xfer.aToken[1]), 0);
+      }else
+
+
+      /*    private
+      **
+      ** The server tells the client that the next "file" or "cfile" will
+      ** contain private content.
+      */
+      if( blob_eq(&xfer.aToken[0], "private") ){
+        xfer.nextIsPrivate = 1;
+      }else
+
+
+      /*    clone_seqno N
+      **
+      ** When doing a clone, the server tries to send all of its artifacts
+      ** in sequence.  This card indicates the sequence number of the next
+      ** blob that needs to be sent.  If N<=0 that indicates that all blobs
+      ** have been sent.
+      */
+      if( blob_eq(&xfer.aToken[0], "clone_seqno") && xfer.nToken==2 ){
+        blob_is_int(&xfer.aToken[1], &cloneSeqno);
+        if( cloneSeqno<0 ){
+          xfer_fatal_error("invalid clone_seqno");
+          return ++nErr;
+        }
+      }else
+
+      /*   message MESSAGE
+      **
+      ** A message is received from the server.  Print it.
+      ** Similar to "error" but does not stop processing.
+      */
+      if( blob_eq(&xfer.aToken[0],"message") && xfer.nToken==2 ){
+        char *zMsg = blob_terminate(&xfer.aToken[1]);
+        defossilize(zMsg);
+        if( (syncFlags & SYNC_PUSH) && zMsg
+            && sqlite3_strglob("pull only *", zMsg)==0 ){
+          syncFlags &= ~SYNC_PUSH;
+          zMsg = 0;
+        }
+        if( zMsg && zMsg[0] ){
+          fossil_force_newline();
+          fossil_print("Server says: %s\n", zMsg);
+        }
+      }else
+
+      /*    pragma NAME VALUE...
+      **
+      ** The server can send pragmas to try to convey meta-information to
+      ** the client.  These are informational only.  Unknown pragmas are
+      ** silently ignored.
+      */
+      if( blob_eq(&xfer.aToken[0], "pragma") && xfer.nToken>=2 ){
+        /*   pragma server-version VERSION ?DATE? ?TIME?
+        **
+        ** The server announces to the server what version of Fossil it
+        ** is running.  The DATE and TIME are a pure numeric ISO8601 time
+        ** for the specific check-in of the client.
+        */
+        if( xfer.nToken>=3 && blob_eq(&xfer.aToken[1], "server-version") ){
+          xfer.remoteVersion = g.syncInfo.remoteVersion =
+            atoi(blob_str(&xfer.aToken[2]));
+          if( xfer.nToken>=5 ){
+            xfer.remoteDate = atoi(blob_str(&xfer.aToken[3]));
+            xfer.remoteTime = atoi(blob_str(&xfer.aToken[4]));
+          }
+          xfer_xflc_check( xfer.remoteVersion, xfer.remoteDate,
+                           xfer.remoteTime, 0x08 );
+        }
+
+        /*   pragma uv-pull-only
+        **   pragma uv-push-ok
+        **
+        ** If the server is unwilling to accept new unversioned content (because
+        ** this client lacks the necessary permissions) then it sends a
+        ** "uv-pull-only" pragma so that the client will know not to waste
+        ** bandwidth trying to upload unversioned content.  If the server
+        ** does accept new unversioned content, it sends "uv-push-ok".
+        */
+        else if( syncFlags & SYNC_UNVERSIONED ){
+          if( blob_eq(&xfer.aToken[1], "uv-pull-only") ){
+            uvPullOnly = 1;
+            if( syncFlags & SYNC_UV_REVERT ) uvDoPush = 1;
+          }else if( blob_eq(&xfer.aToken[1], "uv-push-ok") ){
+            uvDoPush = 1;
+          }
+        }
+
+        /*    pragma ci-lock-fail  USER-HOLDING-LOCK  LOCK-TIME
+        **
+        ** The server generates this message when a "pragma ci-lock"
+        ** is attempted on a check-in for which there is an existing
+        ** lock.  USER-HOLDING-LOCK is the name of the user who originated
+        ** the lock, and LOCK-TIME is the timestamp (seconds since 1970)
+        ** when the lock was taken.
+        */
+        else if( blob_eq(&xfer.aToken[1], "ci-lock-fail") && xfer.nToken==4 ){
+          char *zUser = blob_terminate(&xfer.aToken[2]);
+          sqlite3_int64 mtime, iNow;
+          defossilize(zUser);
+          iNow = time(NULL);
+          if( blob_is_int64(&xfer.aToken[3], &mtime) && iNow>mtime ){
+            if( mtime<0 ){
+              xfer_fatal_error("invalid ci-lock-fail time");
+              return ++nErr;
+            }
+            iNow = time(NULL);
+            fossil_print("\nParent check-in locked by %s %s ago\n",
+               zUser, human_readable_age((iNow+1-mtime)/86400.0));
+          }else{
+            fossil_print("\nParent check-in locked by %s\n", zUser);
+          }
+          g.ckinLockFail = fossil_strdup(zUser);
+        }
+
+        /*    pragma avoid-delta-manifests
+        **
+        ** Discourage the use of delta manifests.  The remote side sends
+        ** this pragma when its forbid-delta-manifests setting is true.
+        */
+        else if( blob_eq(&xfer.aToken[1], "avoid-delta-manifests") ){
+          g.bAvoidDeltaManifests = 1;
+        }
+
+        /*    pragma link URL ARG MTIME
+        **
+        ** The server has sent the URL for a link to another repository.
+        ** Record this as a link:URL entry in the config table.
+        */
+        else if( blob_eq(&xfer.aToken[1], "link")
+              && xfer.nToken==5
+              && (syncFlags & SYNC_SHARE_LINKS)!=0
+        ){
+          UrlData x;
+          char *zUrl = blob_str(&xfer.aToken[2]);
+          char *zArg = blob_str(&xfer.aToken[3]);
+          i64 iTime = strtoll(blob_str(&xfer.aToken[4]),0,0);
+          memset(&x, 0, sizeof(x));
+          defossilize(zUrl);
+          defossilize(zArg);
+          url_parse_local(zUrl, URL_OMIT_USER, &x);
+          if( x.protocol
+           && strncmp(x.protocol,"http",4)==0
+           && iTime>0
+          ){
+            db_unprotect(PROTECT_CONFIG);
+            db_multi_exec(
+              "INSERT INTO config(name,value,mtime)\n"
+              " VALUES('link:%q',%Q,%lld)\n"
+              " ON CONFLICT DO UPDATE\n"
+              "   SET value=excluded.value, mtime=excluded.mtime\n"
+              "   WHERE mtime<excluded.mtime;",
+              zUrl, zArg, iTime
+            );
+            db_protect_pop();
+          }
+          url_unparse(&x);
+        }
+
+      }else
+
+      /*   error MESSAGE
+      **
+      ** The server is reporting an error.  The client will abandon
+      ** the sync session.
+      **
+      ** Except, when cloning we will sometimes get an error on the
+      ** first message exchange because the project-code is unknown
+      ** and so the login card on the request was invalid.  The project-code
+      ** is returned in the reply before the error card, so second and
+      ** subsequent messages should be OK.  Nevertheless, we need to ignore
+      ** the error card on the first message of a clone.
+      **
+      ** Also ignore "not authorized to write" errors if this is an
+      ** autopush following a commit.
+      */
+      if( blob_eq(&xfer.aToken[0],"error") && xfer.nToken==2 ){
+        char *zMsg = blob_terminate(&xfer.aToken[1]);
+        defossilize(zMsg);
+        if( (syncFlags & SYNC_IFABLE)!=0
+         && sqlite3_strlike("%not authorized to write%",zMsg,0)==0 ){
+          autopushFailed = 1;
+          nErr++;
+        }else if( (syncFlags & SYNC_CLONE)==0 || nCycle>0 ){
+          fossil_force_newline();
+          fossil_print("Error: %s\n", zMsg);
+          blob_appendf(&xfer.err, "server says: %s\n", zMsg);
+          nErr++;
+          break;
+        }
+      }else
+
+      /* Unknown message */
+      if( xfer.nToken>0 ){
+        if( blob_str(&xfer.aToken[0])[0]=='<' ){
+          fossil_warning(
+            "server replies with HTML instead of fossil sync protocol:\n%b",
+            &recv
+          );
+          nErr++;
+          break;
+        }
+        blob_appendf(&xfer.err, "unknown command: [%b]\n", &xfer.line);
+      }
+
+      if( blob_size(&xfer.err) ){
+        fossil_force_newline();
+        fossil_warning("%b", &xfer.err);
+        nErr++;
+        break;
+      }
+      blobarray_reset(xfer.aToken, xfer.nToken);
+      blob_reset(&xfer.line);
+    }
+    origConfigRcvMask = 0;
+    if( nCardRcvd>0 && (syncFlags & SYNC_VERBOSE) ){
+      fossil_print(zValueFormat /*works-like:"%s%d%d%d%d"*/, "Received:",
+                   blob_size(&recv), nCardRcvd,
+                   xfer.nFileRcvd, xfer.nDeltaRcvd + xfer.nDanglingFile);
+    }else if( syncFlags & SYNC_QUIET ){
+      /* No-op */
+    }else{
+      if( bOutIsTty!=0 ){
+        fossil_print(zBriefFormat /*works-like:"%d%d%d"*/,
+                     nRoundtrip, nArtifactSent, nArtifactRcvd);
+      }
+    }
+    nUncRcvd += blob_size(&recv);
+    blob_reset(&recv);
+    nCycle++;
+
+    /* Set go to 1 if we need to continue the sync/push/pull/clone for
+    ** another round.  Set go to 0 if it is time to quit. */
+    nFileRecv = xfer.nFileRcvd + xfer.nDeltaRcvd + xfer.nDanglingFile;
+    if( (nFileRecv>0 || newPhantom) && db_exists("SELECT 1 FROM phantom") ){
+      go = 1;
+      mxPhantomReq = nFileRecv*2;
+      if( mxPhantomReq<200 ) mxPhantomReq = 200;
+    }else if( xfer.nFileSent+xfer.nDeltaSent>0 || uvDoPush ){
+      /* Go another round if files are queued to send */
+      go = 1;
+    }else if( xfer.nPrivIGot>0 && nCycle==1 ){
+      go = 1;
+    }else if( nUvGimmeSent>0 && (nUvFileRcvd>0 || nCycle<3) ){
+      /* Continue looping as long as new uvfile cards are being received
+      ** and uvgimme cards are being sent. */
+      go = 1;
+    }else if( (syncFlags & SYNC_CLONE)!=0 ){
+      if( nCycle==1 ){
+        go = 1;   /* go at least two rounds on a clone */
+      }else if( nFileRecv>0 ){
+        go = 1;
+      }else if( cloneSeqno>0 && nArtifactRcvd>nPriorArtifact ){
+        /* Continue the clone until we see the clone_seqno 0" card or
+        ** until we stop receiving artifacts */
+        go = 1;
+      }
+    }
+
+    nCardRcvd = 0;
+    xfer.nFileRcvd = 0;
+    xfer.nDeltaRcvd = 0;
+    xfer.nDanglingFile = 0;
+    db_multi_exec("DROP TABLE onremote; DROP TABLE unk;");
+    if( go ){
+      manifest_crosslink_end(MC_PERMIT_HOOKS);
+    }else{
+      manifest_crosslink_end(MC_PERMIT_HOOKS);
+      content_enable_dephantomize(1);
+    }
+    db_end_transaction(0);
+  }; /* while(go) */
+  transport_stats(&nSent, &nRcvd, 1);
+  if( pnRcvd ) *pnRcvd = nArtifactRcvd;
+  if( (rSkew*24.0*3600.0) > 10.0 ){
+     fossil_warning("*** time skew *** server is fast by %s",
+                    db_timespan_name(rSkew));
+     g.clockSkewSeen = 1;
+  }else if( rSkew*24.0*3600.0 < -10.0 ){
+     fossil_warning("*** time skew *** server is slow by %s",
+                    db_timespan_name(-rSkew));
+     g.clockSkewSeen = 1;
+  }
+  if( bOutIsTty==0 && (syncFlags & SYNC_QUIET)==0 ){
+    fossil_print(zBriefFormat /*works-like:"%d%d%d"*/,
+                 nRoundtrip, nArtifactSent, nArtifactRcvd);
+    fossil_force_newline();
+  }
+  fossil_force_newline();
+  if( g.zHttpCmd==0 ){
+    if( syncFlags & SYNC_QUIET ){
+      /* no-op */
+    }else if( syncFlags & SYNC_VERBOSE ){
+      fossil_print(
+        "%s done, wire bytes sent: %lld  received: %lld  remote: %s%s\n",
+        zOpType, nSent, nRcvd,
+        (g.url.name && g.url.name[0]!='\0') ? g.url.name : "",
+        (g.zIpAddr && g.zIpAddr[0]!='\0'
+          && fossil_strcmp(g.zIpAddr, g.url.name))
+          ? mprintf(" (%s)", g.zIpAddr) : "");
+    }else{
+      fossil_print(
+        "%s done, wire bytes sent: %lld  received: %lld  remote: %s\n",
+          zOpType, nSent, nRcvd, g.zIpAddr);
+    }
+  }
+  if( syncFlags & SYNC_VERBOSE ){
+    fossil_print(
+      "Uncompressed payload sent: %lld  received: %lld\n", nUncSent, nUncRcvd);
+  }
+  blob_reset(&send);
+  blob_reset(&recv);
+  transport_close(&g.url);
+  transport_global_shutdown(&g.url);
+  if( nErr && go==2 ){
+    db_multi_exec("DROP TABLE onremote; DROP TABLE unk;");
+    manifest_crosslink_end(MC_PERMIT_HOOKS);
+    content_enable_dephantomize(1);
+    db_end_transaction(0);
+  }
+  if( nErr && autopushFailed ){
+    fossil_warning(
+      "Warning: The check-in was successful and is saved locally but you\n"
+      "         are not authorized to push the changes back to the server\n"
+      "         at %s",
+      g.url.canonical
+    );
+    nErr--;
+  }
+  if( (syncFlags & SYNC_CLONE)==0 && g.rcvid && fossil_any_has_fork(g.rcvid) ){
+    fossil_warning("***** WARNING: a fork has occurred *****\n"
+                   "use \"fossil leaves -multiple\" for more details.");
+  }
+  return nErr;
+}