I think the "--once" option for sync/pull/push will be useful for synchronizing forks. E.g.,

$ fossil remote-url
http://example.com/fossil-fork

$ fossil pull --once http://www.fossil-scm.org
...
Total network traffic: 318 bytes sent, 1292 bytes received

$ fossil remote-url
http://example.com/fossil-fork

Diff:

--- src/sync.c
+++ src/sync.c
@@ -67,14 +67,17 @@
 /*
 ** This routine processes the command-line argument for push, pull,
 ** and sync.  If a command-line argument is given, that is the URL
 ** of a server to sync against.  If no argument is given, use the
 ** most recently synced URL.  Remember the current URL for next time.
+**
+** If --once option is specified, do not remember URL.
 */
 void process_sync_args(void){
   const char *zUrl = 0;
   int urlOptional = find_option("autourl",0,0)!=0;
+  int syncOnce = find_option("once",0,0)!=0;
   url_proxy_options();
   db_find_and_open_repository(1);
   if( g.argc==2 ){
     zUrl = db_get("last-sync-url", 0);
   }else if( g.argc==3 ){
@@ -83,11 +86,13 @@
   if( zUrl==0 ){
     if( urlOptional ) exit(0);
     usage("URL");
   }
   url_parse(zUrl);
-  db_set("last-sync-url", g.urlIsFile ? g.urlCanonical : zUrl, 0);
+  if ( syncOnce==0 ) {
+    db_set("last-sync-url", g.urlIsFile ? g.urlCanonical : zUrl, 0);
+  }
   user_select();
   if( g.argc==2 ){
     if( g.urlPort!=g.urlDfltPort ){
       printf("Server:    %s://%s:%d%s\n",
               g.urlProtocol, g.urlName, g.urlPort, g.urlPath);
@@ -99,16 +104,18 @@
 }
 
 /*
 ** COMMAND: pull
 **
-** Usage: %fossil pull ?URL? ?-R|--respository REPOSITORY?
+** Usage: %fossil pull ?URL? ?-R|--respository REPOSITORY? ?--once?
 **
 ** Pull changes from a remote repository into the local repository.
 **
 ** If the URL is not specified, then the URL from the most recent
 ** clone, push, pull, remote-url, or sync command is used.
+**
+** If --once option is specified, do not remember URL.
 **
 ** See also: clone, push, sync, remote-url
 */
 void pull_cmd(void){
   process_sync_args();
@@ -116,16 +123,18 @@
 }
 
 /*
 ** COMMAND: push
 **
-** Usage: %fossil push ?URL? ?-R|--repository REPOSITORY?
+** Usage: %fossil push ?URL? ?-R|--repository REPOSITORY? ?--once?
 **
 ** Push changes in the local repository over into a remote repository.
 **
 ** If the URL is not specified, then the URL from the most recent
 ** clone, push, pull, remote-url, or sync command is used.
+**
+** If --once option is specified, do not remember URL.
 **
 ** See also: clone, pull, sync, remote-url
 */
 void push_cmd(void){
   process_sync_args();
@@ -134,11 +143,11 @@
 
 
 /*
 ** COMMAND: sync
 **
-** Usage: %fossil sync ?URL? ?-R|--repository REPOSITORY?
+** Usage: %fossil sync ?URL? ?-R|--repository REPOSITORY? ?--once?
 **
 ** Synchronize the local repository with a remote repository.  This is
 ** the equivalent of running both "push" and "pull" at the same time.
 **
 ** If a user-id and password are required, specify them as follows:
@@ -145,10 +154,12 @@
 **
 **     http://userid:password@www.domain.com:1234/path
 **
 ** If the URL is not specified, then the URL from the most recent successful
 ** clone, push, pull, remote-url, or sync command is used.
+**
+** If --once option is specified, do not remember URL.
 **
 ** See also:  clone, push, pull, remote-url
 */
 void sync_cmd(void){
   process_sync_args();

drh added on 2009-11-06 14:16:01:
check-in 5153d618937eb274b06a5cb2ae93fa0832157575

dmitry added on 2009-11-06 15:31:13:
Thanks! The funny thing is that the original patch was almost exactly the same (with dontSaveUrl variable), but I changed it for some reason :)