Force-with-lease and new branches

[John Keeping <john@keeping.me.uk>]

I've noticed a slightly annoying behaviour of git-push's
--force-with-lease option around branch creation.

I'd like to be able to do:

	git push --force-with-lease origin refs/heads/jk/*

to push out a load of topic branches safely in case I've switched client
machines and forgotten to pull, but for newly-created branches this
fails with "stale-info", which seems to be intentional via the
expect_old_no_trackback field in struct ref.

However, if I use the explicit --force-with-lease syntax with the null
hash then the push does succeed.  I've added a couple of tests to t5533
which demonstrate this in a patch below - the first one fails but the
second passes.

It looks like this has been the case since the first version of what
would become --force-with-lease [1] and I can't find any discussion
around this particular behaviour in the three versions of that patch set
I found on Gmane [2], [3], [4].

So my questions are: what will break if we decide to treat "no remote
tracking branch" as "new branch" and is that a reasonable thing to do?


[1] http://article.gmane.org/gmane.comp.version-control.git/229992
[2] http://article.gmane.org/gmane.comp.version-control.git/229430
[3] http://article.gmane.org/gmane.comp.version-control.git/230142
[4] http://article.gmane.org/gmane.comp.version-control.git/231021


-- >8 --
diff --git a/t/t5533-push-cas.sh b/t/t5533-push-cas.sh
index c732012..ad9e06f 100755
--- a/t/t5533-push-cas.sh
+++ b/t/t5533-push-cas.sh
@@ -191,4 +191,28 @@ test_expect_success 'cover everything with default force-with-lease (allowed)' '
 	test_cmp expect actual
 '
 
+test_expect_success 'new branch covered by force-with-lease' '
+	setup_srcdst_basic &&
+	(
+		cd dst &&
+		git branch branch master &&
+		git push --force-with-lease=branch origin branch
+	) &&
+	git ls-remote dst refs/heads/branch >expect &&
+	git ls-remote src refs/heads/branch >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'new branch with explicit force-with-lease' '
+	setup_srcdst_basic &&
+	(
+		cd dst &&
+		git branch branch master &&
+		git push --force-with-lease=branch:0000000000000000000000000000000000000000 origin branch
+	) &&
+	git ls-remote dst refs/heads/branch >expect &&
+	git ls-remote src refs/heads/branch >actual &&
+	test_cmp expect actual
+'
+
 test_done