request-pull: warn if the remote object is not the same as the local one

In some cases, git request-pull might be invoked with remote and
local objects that differ even though they point to the same commit.
For example, the remote object might be a lightweight tag
vs. an annotated tag on the local side; or the user might have
reworded the tag locally and forgotten to push it.

When this happens git-request-pull will not warn, because it only
checks that "git ls-remote" returns an SHA1 that matches the local
commit (known as $headrev in the script).  This patch makes
git-request-pull retrieve the tag object SHA1 while processing
the "git ls-remote" output, so that it can be matched against the
local object.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/t/t5150-request-pull.sh b/t/t5150-request-pull.sh
index c1a821a549..852dcd913f 100755
--- a/t/t5150-request-pull.sh
+++ b/t/t5150-request-pull.sh
@@ -264,4 +264,39 @@ test_expect_success 'request-pull quotes regex metacharacters properly' '
 
 '
 
+test_expect_success 'pull request with mismatched object' '
+
+	rm -fr downstream.git &&
+	git init --bare downstream.git &&
+	(
+		cd local &&
+		git checkout initial &&
+		git merge --ff-only master &&
+		git push origin HEAD:refs/tags/full &&
+		test_must_fail git request-pull initial "$downstream_url" tags/full \
+			2>../err
+	) &&
+	grep "points to a different object" err &&
+	grep "Are you sure you pushed" err
+
+'
+
+test_expect_success 'pull request with stale object' '
+
+	rm -fr downstream.git &&
+	git init --bare downstream.git &&
+	(
+		cd local &&
+		git checkout initial &&
+		git merge --ff-only master &&
+		git push origin refs/tags/full &&
+		git tag -f -m"Thirty-one days" full &&
+		test_must_fail git request-pull initial "$downstream_url" tags/full \
+			2>../err
+	) &&
+	grep "points to a different object" err &&
+	grep "Are you sure you pushed" err
+
+'
+
 test_done