Subject: [PATCH v3 0/2] remote.c: remove erroneous BUG case

From: Denton Liu <[email-masked]>
Date: Tue, 5 Aug 2025 21:53:36 -0700

In the case where one pushes a non-existent oid to an unqualified
destination, we encounter the following BUG

	error: The destination you provided is not a full refname (i.e.,
	starting with "refs/"). We tried to guess what you meant by:

	- Looking for a ref that matches 'branch' on the remote side.
	- Checking if the <src> being pushed ('0000000000000000000000000000000000000001')
	  is a ref in "refs/{heads,tags}/". If so we add a corresponding
	  refs/{heads,tags}/ prefix on the remote side.

	Neither worked, so we gave up. You must fully qualify the ref.
	BUG: remote.c:1221: '0000000000000000000000000000000000000001' should be commit/tag/tree/blob, is '-1'
	fatal: the remote end hung up unexpectedly
	Aborted (core dumped)

However, this isn't actually a bug so replace it with an advise()
message.

Changes since v2:

* Add t5516 cleanup patch
* Squash test creation patch into the patch that fixes it
* Include the erroneous object ID in the advise message

Denton Liu (2):
  t5516: remove surrounding empty lines in test bodies
  remote.c: remove BUG in show_push_unqualified_ref_name_error()

 remote.c              |  4 ++--
 t/t5516-fetch-push.sh | 54 ++++---------------------------------------
 2 files changed, 6 insertions(+), 52 deletions(-)

Range-diff against v2:
1:  d26f355c19 ! 1:  82b09af4ca t5516: introduce 'push ref expression with non-existent oid src'
    @@ Metadata
     Author: Denton Liu <[email-masked]>
     
      ## Commit message ##
    -    t5516: introduce 'push ref expression with non-existent oid src'
    +    t5516: remove surrounding empty lines in test bodies
     
    -    It is possible to trigger a Git bug by pushing a refspec where the
    -    source is an oid that's non-existent. An example of the error message
    -    produced is as follows:
    -
    -            error: The destination you provided is not a full refname (i.e.,
    -            starting with "refs/"). We tried to guess what you meant by:
    -
    -            - Looking for a ref that matches 'branch' on the remote side.
    -            - Checking if the <src> being pushed ('0000000000000000000000000000000000000001')
    -              is a ref in "refs/{heads,tags}/". If so we add a corresponding
    -              refs/{heads,tags}/ prefix on the remote side.
    -
    -            Neither worked, so we gave up. You must fully qualify the ref.
    -            BUG: remote.c:1221: '0000000000000000000000000000000000000001' should be commit/tag/tree/blob, is '-1'
    -            fatal: the remote end hung up unexpectedly
    -            Aborted (core dumped)
    -
    -    Document this failure in a test case so that it can be confirmed fixed
    -    later.
    +    This style with the empty lines in test bodies was from when the test
    +    suite was being developed. Remove the empty lines to match the modern
    +    test style.
     
      ## t/t5516-fetch-push.sh ##
    -@@ t/t5516-fetch-push.sh: test_expect_success 'push ref expression with non-existent, incomplete dest' '
    +@@ t/t5516-fetch-push.sh: check_push_result () {
    + }
      
    + test_expect_success setup '
    +-
    + 	>path1 &&
    + 	git add path1 &&
    + 	test_tick &&
    +@@ t/t5516-fetch-push.sh: test_expect_success setup '
    + 	test_tick &&
    + 	git commit -a -m second &&
    + 	the_commit=$(git show-ref -s --verify refs/heads/main)
    +-
      '
      
    -+test_expect_failure 'push ref expression with non-existent oid src' '
    -+
    -+	mk_test testrepo &&
    -+	test_must_fail git push testrepo $(test_oid 001):branch
    -+
    -+'
    -+
    - for head in HEAD @
    - do
    + for cmd in push fetch
    +@@ t/t5516-fetch-push.sh: test_expect_success 'push with pushInsteadOf and explicit pushurl (pushInsteadOf
    + '
      
    + test_expect_success 'push with matching heads' '
    +-
    + 	mk_test testrepo heads/main &&
    + 	git push testrepo : &&
    + 	check_push_result testrepo $the_commit heads/main
    +-
    + '
    + 
    + test_expect_success 'push with matching heads on the command line' '
    +-
    + 	mk_test testrepo heads/main &&
    + 	git push testrepo : &&
    + 	check_push_result testrepo $the_commit heads/main
    +-
    + '
    + 
    + test_expect_success 'failed (non-fast-forward) push with matching heads' '
    +-
    + 	mk_test testrepo heads/main &&
    + 	git push testrepo : &&
    + 	git commit --amend -massaged &&
    + 	test_must_fail git push testrepo &&
    + 	check_push_result testrepo $the_commit heads/main &&
    + 	git reset --hard $the_commit
    +-
    + '
    + 
    + test_expect_success 'push --force with matching heads' '
    +-
    + 	mk_test testrepo heads/main &&
    + 	git push testrepo : &&
    + 	git commit --amend -massaged &&
    + 	git push --force testrepo : &&
    + 	! check_push_result testrepo $the_commit heads/main &&
    + 	git reset --hard $the_commit
    +-
    + '
    + 
    + test_expect_success 'push with matching heads and forced update' '
    +-
    + 	mk_test testrepo heads/main &&
    + 	git push testrepo : &&
    + 	git commit --amend -massaged &&
    + 	git push testrepo +: &&
    + 	! check_push_result testrepo $the_commit heads/main &&
    + 	git reset --hard $the_commit
    +-
    + '
    + 
    + test_expect_success 'push with no ambiguity (1)' '
    +-
    + 	mk_test testrepo heads/main &&
    + 	git push testrepo main:main &&
    + 	check_push_result testrepo $the_commit heads/main
    +-
    + '
    + 
    + test_expect_success 'push with no ambiguity (2)' '
    +-
    + 	mk_test testrepo remotes/origin/main &&
    + 	git push testrepo main:origin/main &&
    + 	check_push_result testrepo $the_commit remotes/origin/main
    +-
    + '
    + 
    + test_expect_success 'push with colon-less refspec, no ambiguity' '
    +-
    + 	mk_test testrepo heads/main heads/t/main &&
    + 	git branch -f t/main main &&
    + 	git push testrepo main &&
    + 	check_push_result testrepo $the_commit heads/main &&
    + 	check_push_result testrepo $the_first_commit heads/t/main
    +-
    + '
    + 
    + test_expect_success 'push with weak ambiguity (1)' '
    +-
    + 	mk_test testrepo heads/main remotes/origin/main &&
    + 	git push testrepo main:main &&
    + 	check_push_result testrepo $the_commit heads/main &&
    + 	check_push_result testrepo $the_first_commit remotes/origin/main
    +-
    + '
    + 
    + test_expect_success 'push with weak ambiguity (2)' '
    +-
    + 	mk_test testrepo heads/main remotes/origin/main remotes/another/main &&
    + 	git push testrepo main:main &&
    + 	check_push_result testrepo $the_commit heads/main &&
    + 	check_push_result testrepo $the_first_commit remotes/origin/main remotes/another/main
    +-
    + '
    + 
    + test_expect_success 'push with ambiguity' '
    +-
    + 	mk_test testrepo heads/frotz tags/frotz &&
    + 	test_must_fail git push testrepo main:frotz &&
    + 	check_push_result testrepo $the_first_commit heads/frotz tags/frotz
    +-
    + '
    + 
    + test_expect_success 'push with onelevel ref' '
    +@@ t/t5516-fetch-push.sh: test_expect_success 'push with onelevel ref' '
    + '
    + 
    + test_expect_success 'push with colon-less refspec (1)' '
    +-
    + 	mk_test testrepo heads/frotz tags/frotz &&
    + 	git branch -f frotz main &&
    + 	git push testrepo frotz &&
    + 	check_push_result testrepo $the_commit heads/frotz &&
    + 	check_push_result testrepo $the_first_commit tags/frotz
    +-
    + '
    + 
    + test_expect_success 'push with colon-less refspec (2)' '
    +-
    + 	mk_test testrepo heads/frotz tags/frotz &&
    + 	if git show-ref --verify -q refs/heads/frotz
    + 	then
    +@@ t/t5516-fetch-push.sh: test_expect_success 'push with colon-less refspec (2)' '
    + 	git push -f testrepo frotz &&
    + 	check_push_result testrepo $the_commit tags/frotz &&
    + 	check_push_result testrepo $the_first_commit heads/frotz
    +-
    + '
    + 
    + test_expect_success 'push with colon-less refspec (3)' '
    +@@ t/t5516-fetch-push.sh: test_expect_success 'push with colon-less refspec (3)' '
    + '
    + 
    + test_expect_success 'push with colon-less refspec (4)' '
    +-
    + 	mk_test testrepo &&
    + 	if git show-ref --verify -q refs/heads/frotz
    + 	then
    +@@ t/t5516-fetch-push.sh: test_expect_success 'push with colon-less refspec (4)' '
    + 	git push testrepo frotz &&
    + 	check_push_result testrepo $the_commit tags/frotz &&
    + 	test 1 = $( cd testrepo && git show-ref | wc -l )
    +-
    + '
    + 
    + test_expect_success 'push head with non-existent, incomplete dest' '
    +-
    + 	mk_test testrepo &&
    + 	git push testrepo main:branch &&
    + 	check_push_result testrepo $the_commit heads/branch
    +-
    + '
    + 
    + test_expect_success 'push tag with non-existent, incomplete dest' '
    +-
    + 	mk_test testrepo &&
    + 	git tag -f v1.0 &&
    + 	git push testrepo v1.0:tag &&
    + 	check_push_result testrepo $the_commit tags/tag
    +-
    + '
    + 
    + test_expect_success 'push oid with non-existent, incomplete dest' '
    +-
    + 	mk_test testrepo &&
    + 	test_must_fail git push testrepo $(git rev-parse main):foo
    +-
    + '
    + 
    + test_expect_success 'push ref expression with non-existent, incomplete dest' '
    +-
    + 	mk_test testrepo &&
    + 	test_must_fail git push testrepo main^:branch
    +-
    + '
    + 
    + for head in HEAD @
    +@@ t/t5516-fetch-push.sh: do
    + 		git checkout main &&
    + 		git push testrepo $head:branch &&
    + 		check_push_result testrepo $the_commit heads/branch
    +-
    + 	'
    + 
    + 	test_expect_success "push with config remote.*.push = $head" '
    +@@ t/t5516-fetch-push.sh: test_expect_success 'push with remote.pushdefault' '
    + '
    + 
    + test_expect_success 'push with config remote.*.pushurl' '
    +-
    + 	mk_test testrepo heads/main &&
    + 	git checkout main &&
    + 	test_config remote.there.url test2repo &&
    +@@ t/t5516-fetch-push.sh: test_expect_success 'push ignores "branch." config without subsection' '
    + '
    + 
    + test_expect_success 'push with dry-run' '
    +-
    + 	mk_test testrepo heads/main &&
    + 	old_commit=$(git -C testrepo show-ref -s --verify refs/heads/main) &&
    + 	git push --dry-run testrepo : &&
    +@@ t/t5516-fetch-push.sh: test_expect_success 'push with dry-run' '
    + '
    + 
    + test_expect_success 'push updates local refs' '
    +-
    + 	mk_test testrepo heads/main &&
    + 	mk_child testrepo child &&
    + 	(
    +@@ t/t5516-fetch-push.sh: test_expect_success 'push updates local refs' '
    + 		test $(git rev-parse main) = \
    + 			$(git rev-parse remotes/origin/main)
    + 	)
    +-
    + '
    + 
    + test_expect_success 'push updates up-to-date local refs' '
    +-
    + 	mk_test testrepo heads/main &&
    + 	mk_child testrepo child1 &&
    + 	mk_child testrepo child2 &&
    +@@ t/t5516-fetch-push.sh: test_expect_success 'push updates up-to-date local refs' '
    + 		test $(git rev-parse main) = \
    + 			$(git rev-parse remotes/origin/main)
    + 	)
    +-
    + '
    + 
    + test_expect_success 'push preserves up-to-date packed refs' '
    +-
    + 	mk_test testrepo heads/main &&
    + 	mk_child testrepo child &&
    + 	(
    +@@ t/t5516-fetch-push.sh: test_expect_success 'push preserves up-to-date packed refs' '
    + 		git push &&
    + 		! test -f .git/refs/remotes/origin/main
    + 	)
    +-
    + '
    + 
    + test_expect_success 'push does not update local refs on failure' '
    +-
    + 	mk_test testrepo heads/main &&
    + 	mk_child testrepo child &&
    + 	echo "#!/no/frobnication/today" >testrepo/.git/hooks/pre-receive &&
    +@@ t/t5516-fetch-push.sh: test_expect_success 'push does not update local refs on failure' '
    + 		test $(git rev-parse main) != \
    + 			$(git rev-parse remotes/origin/main)
    + 	)
    +-
    + '
    + 
    + test_expect_success 'allow deleting an invalid remote ref' '
    +-
    + 	mk_test testrepo heads/branch &&
    + 	rm -f testrepo/.git/objects/??/* &&
    + 	git push testrepo :refs/heads/branch &&
    + 	(cd testrepo && test_must_fail git rev-parse --verify refs/heads/branch)
    +-
    + '
    + 
    + test_expect_success 'pushing valid refs triggers post-receive and post-update hooks' '
2:  2bd892b26c ! 2:  938dfb8d4e remote.c: remove BUG in show_push_unqualified_ref_name_error()
    @@ Commit message
         is wrong.  It is an ordinary end-user mistake to give an object
         name that does not exist and treated as such.
     
    +    An example of the error message produced is as follows:
    +
    +            error: The destination you provided is not a full refname (i.e.,
    +            starting with "refs/"). We tried to guess what you meant by:
    +
    +            - Looking for a ref that matches 'branch' on the remote side.
    +            - Checking if the <src> being pushed ('0000000000000000000000000000000000000001')
    +              is a ref in "refs/{heads,tags}/". If so we add a corresponding
    +              refs/{heads,tags}/ prefix on the remote side.
    +
    +            Neither worked, so we gave up. You must fully qualify the ref.
    +            BUG: remote.c:1221: '0000000000000000000000000000000000000001' should be commit/tag/tree/blob, is '-1'
    +            fatal: the remote end hung up unexpectedly
    +            Aborted (core dumped)
    +
         Helped-by: Junio C Hamano <[email-masked]>
     
      ## remote.c ##
    @@ remote.c: static void show_push_unqualified_ref_name_error(const char *dst_value
      	} else {
     -		BUG("'%s' should be commit/tag/tree/blob, is '%d'",
     -		    matched_src_name, type);
    -+		advise(_("The <src> part of the refspec is an oid that doesn't exist.\n"));
    ++		advise(_("The <src> part of the refspec ('%s') is an object ID that doesn't exist.\n"),
    ++		       matched_src_name);
      	}
      }

      ## t/t5516-fetch-push.sh ##
     @@ t/t5516-fetch-push.sh: test_expect_success 'push ref expression with non-existent, incomplete dest' '
    - 
    + 	test_must_fail git push testrepo main^:branch
      '
      
    --test_expect_failure 'push ref expression with non-existent oid src' '
     +test_expect_success 'push ref expression with non-existent oid src' '
    ++	mk_test testrepo &&
    ++	test_must_fail git push testrepo $(test_oid 001):branch
    ++'
    ++
    + for head in HEAD @
    + do
      
    - 	mk_test testrepo &&
    - 	test_must_fail git push testrepo $(test_oid 001):branch
-- 
2.50.1