diff --git a/hgext/hgsql.py b/hgext/hgsql.py
index 4b2f216963..55e9817cce 100644
--- a/hgext/hgsql.py
+++ b/hgext/hgsql.py
@@ -21,9 +21,13 @@ Config::
     syncinterval = -1
 
     # Enable faster "need sync or not" check. It could be 6x faster, and
-    # removes some time in the critial section.
+    # removes some time in the critical section.
     # (default: true)
     fastsynccheck = true
+
+    # Whether to do an initial "best-effort" pull from the database.
+    # (default: true)
+    initialsync = true
 """
 
 
@@ -91,6 +95,7 @@ configitem("hgsql", "bypass", default=False)
 configitem("hgsql", "enabled", default=False)
 configitem("hgsql", "engine", default="innodb")
 configitem("hgsql", "fastsynccheck", default=True)
+configitem("hgsql", "initialsync", default=True)
 configitem("hgsql", "locktimeout", default=60)
 configitem("hgsql", "maxcommitsize", default=52428800)
 configitem("hgsql", "maxinsertsize", default=1048576)
@@ -245,6 +250,10 @@ def extsetup(ui):
             )
         )
 
+    global initialsync
+    if not ui.configbool("hgsql", "initialsync"):
+        initialsync = INITIAL_SYNC_DISABLE
+
     # Directly examining argv seems like a terrible idea, but it seems
     # necessary unless we refactor mercurial dispatch code. This is because
     # the first place we have access to parsed options is in the same function
@@ -252,7 +261,6 @@ def extsetup(ui):
     # the sync operation in which the lock is elided unless we set this.
     if "--forcesync" in sys.argv:
         ui.debug("forcesync enabled\n")
-        global initialsync
         initialsync = INITIAL_SYNC_FORCE
 
 
diff --git a/tests/test-hgsql-pushrebase2.t b/tests/test-hgsql-pushrebase2.t
new file mode 100644
index 0000000000..a22feb7fc9
--- /dev/null
+++ b/tests/test-hgsql-pushrebase2.t
@@ -0,0 +1,109 @@
+#require no-windows
+
+Test:
+1. Process X is handling a pushrebase request.
+2. While running prepushrebase hooks, the local repo and the database were updated.
+3. Process X enters the critical section and thinks the local repo is
+up-to-date while some internal states might be not.
+
+  $ shorttraceback
+  $ . "$TESTDIR/hgsql/library.sh"
+  $ enable treemanifest remotefilelog remotenames pushrebase
+  $ setconfig hgsql.initialsync=false treemanifest.treeonly=1 treemanifest.sendtrees=1 remotefilelog.reponame=x remotefilelog.cachepath=$TESTTMP/cache ui.ssh="python $TESTDIR/dummyssh" pushrebase.verbose=1 experimental.bundle2lazylocking=True
+
+  $ newrepo state1
+  $ echo remotefilelog >> .hg/requires
+  $ hg debugdrawdag << 'EOS'
+  > A
+  > EOS
+
+  $ newrepo state2
+  $ echo remotefilelog >> .hg/requires
+  $ hg debugdrawdag << 'EOS'
+  > B
+  > |
+  > A
+  > EOS
+
+  $ newrepo state3
+  $ echo remotefilelog >> .hg/requires
+  $ hg debugdrawdag << 'EOS'
+  > B C
+  > |/
+  > A
+  > EOS
+
+  $ cd $TESTTMP
+  $ initserver serverrepo master
+
+Update the server repo and the database to state1.
+
+  $ cd $TESTTMP/serverrepo
+  $ setconfig treemanifest.server=1
+  $ hg pull -r tip $TESTTMP/state1 -q
+  $ hg bookmark -r tip master
+
+Prepare the prepushrebase hook to update the server repo and the database.
+
+  $ cat > $TESTTMP/update-to-state2.sh <<EOF
+  > # Bypass pushrebase logic that enforces a bundle repo
+  > unset HG_HOOK_BUNDLEPATH
+  > # Update the server repo and the database to state2
+  > hg pull --cwd $TESTTMP/serverrepo -R $TESTTMP/serverrepo -r tip $TESTTMP/state2
+  > EOF
+
+Another prepushrebase hook just to warm up in-memory repo states (changelog and
+manifest).
+
+  $ cat > $TESTTMP/prepushrebase.py <<EOF
+  > def warmup(ui, repo, *args, **kwds):
+  >     # Just have some side-effect loading the changelog and manifest
+  >     data = repo['tip']['A'].data()
+  >     ui.write_err('prepushrebase hook called. A = %r\n' % data)
+  > EOF
+
+00manifest.i needs to exist so manifestlog is cacheable. Windows has a
+different filecache implemenation and is excluded.
+
+  $ cd $TESTTMP/serverrepo
+  $ touch .hg/store/00manifest.i
+  $ hg dbsh -c 'repo.manifestlog; print(repo._filecache["manifestlog"]._entries[0].cacheable())'
+  True
+
+  $ cat >> .hg/hgrc << EOF
+  > [hgsql]
+  > verbose=1
+  > [hooks]
+  > prepushrebase.step1=python:$TESTTMP/prepushrebase.py:warmup
+  > prepushrebase.step2=bash $TESTTMP/update-to-state2.sh
+  > EOF
+
+Do the push!
+
+  $ cd $TESTTMP/state3
+  $ hg push -r C --to master ssh://user@dummy/serverrepo
+  pushing rev dc0947a82db8 to destination ssh://user@dummy/serverrepo bookmark master
+  searching for changes
+  remote: prepushrebase hook called. A = 'A'
+  remote: [hgsql] got lock after * seconds (read 1 rows) (glob)
+  remote: pulling from $TESTTMP/state2
+  remote: searching for changes
+  remote: adding changesets
+  remote: adding manifests
+  remote: adding file changes
+  remote: added 1 changesets with 1 changes to 1 files
+  remote: new changesets 112478962961
+  remote: (run 'hg update' to get a working copy)
+  remote: [hgsql] held lock for * seconds (read 6 rows; write 7 rows) (glob)
+  remote: checking conflicts with 426bada5c675
+  remote: pushing 1 changeset:
+  remote:     dc0947a82db8  C
+  remote: [hgsql] got lock after * seconds (read 1 rows) (glob)
+  remote: rebasing stack from 426bada5c675 onto 426bada5c675
+  remote: transaction abort!
+  remote: rollback completed
+  remote: [hgsql] held lock for * seconds (read 4 rows; write 0 rows) (glob)
+  remote: IntegrityError: 1062 (23000): Duplicate entry 'master-00manifesttree.i-1-0' for key 'PRIMARY'
+  abort: stream ended unexpectedly (got 0 bytes, expected 4)
+  [255]
+
diff --git a/tests/tinit.sh b/tests/tinit.sh
index 79418b348c..0ac5616022 100644
--- a/tests/tinit.sh
+++ b/tests/tinit.sh
@@ -58,7 +58,7 @@ drawdag() {
 # This is useful to match error messages without the traceback.
 shorttraceback() {
   enable errorredirect
-  setconfig errorredirect.script='printf "%s" "$TRACE" | tail -1'
+  setconfig errorredirect.script='printf "%s" "$TRACE" | tail -1 1>&2'
 }
 
 # Set config items like --config way, instead of using cat >> $HGRCPATH