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[PATCH 4/4] am: fix --interactive HEAD tree resolution

From
Jeff King <peff@peff.net>
Date
May 20, 2019, 12:13 UTC
Message-ID
<20190520121301.GD11212@sigill.intra.peff.net>
In-Reply-To
<20190520120636.GA12634@sigill.intra.peff.net>

In interactive mode, "git am -i --resolved" will try to generate a patch based on what is in the index, so that it can prompt "apply this patch?". To do so it needs the tree of HEAD, which it tries to get with get_oid_tree(). However, this doesn't yield a tree oid; the "tree" part just means "if you must disambiguate short oids, then prefer trees" (and we do not need to disambiguate at all, since we are feeding a ref name).

Instead, we must parse the oid as a commit (which should always be true in a non-corrupt repository), and access its tree pointer manually.

This has been broken since the conversion to C in 7ff2683253 (builtin-am: implement -i/--interactive, 2015-08-04), but there was no test coverage because of interactive-mode's insistence on having a tty. That was lifted in the previous commit, so we can now add a test for this case.

Note that before this patch, the test would result in a BUG() which comes from 3506dc9445 (has_uncommitted_changes(): fall back to empty tree, 2018-07-11). But before that, we'd have simply segfaulted (and in fact this is the exact type of case the BUG() added there was trying to catch!).

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/am.c              | 14 ++++++++---
 t/t4257-am-interactive.sh | 49 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 3 deletions(-)
 create mode 100755 t/t4257-am-interactive.sh
diff --git a/builtin/am.c b/builtin/am.c
index ea16b844f1..33bd7a6eab 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1339,9 +1339,17 @@ static void write_index_patch(const struct am_state *state)
 	struct rev_info rev_info;
 	FILE *fp;
 
-	if (!get_oid_tree("HEAD", &head))
-		tree = lookup_tree(the_repository, &head);
-	else
+	if (!get_oid("HEAD", &head)) {
+		struct object *obj;
+		struct commit *commit;
+
+		obj = parse_object_or_die(&head, NULL);
+		commit = object_as_type(the_repository, obj, OBJ_COMMIT, 0);
+		if (!commit)
+			die("unable to parse HEAD as a commit");
+
+		tree = get_commit_tree(commit);
+	} else
 		tree = lookup_tree(the_repository,
 				   the_repository->hash_algo->empty_tree);
 
diff --git a/t/t4257-am-interactive.sh b/t/t4257-am-interactive.sh
new file mode 100755
index 0000000000..6989bf7aba
--- /dev/null
+++ b/t/t4257-am-interactive.sh
@@ -0,0 +1,49 @@
+#!/bin/sh
+
+test_description='am --interactive tests'
+. ./test-lib.sh
+
+test_expect_success 'set up patches to apply' '
+	test_commit unrelated &&
+	test_commit no-conflict &&
+	test_commit conflict-patch file patch &&
+	git format-patch --stdout -2 >mbox &&
+
+	git reset --hard unrelated &&
+	test_commit conflict-master file master base
+'
+
+# Sanity check our setup.
+test_expect_success 'applying all patches generates conflict' '
+	test_must_fail git am mbox &&
+	echo resolved >file &&
+	git add -u &&
+	git am --resolved
+'
+
+test_expect_success 'interactive am can apply a single patch' '
+	git reset --hard base &&
+	printf "%s\n" y n | git am -i mbox &&
+
+	echo no-conflict >expect &&
+	git log -1 --format=%s >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'interactive am can resolve conflict' '
+	git reset --hard base &&
+	printf "%s\n" y y | test_must_fail git am -i mbox &&
+	echo resolved >file &&
+	git add -u &&
+	printf "%s\n" v y | git am -i --resolved &&
+
+	echo conflict-patch >expect &&
+	git log -1 --format=%s >actual &&
+	test_cmp expect actual &&
+
+	echo resolved >expect &&
+	git cat-file blob HEAD:file >actual &&
+	test_cmp expect actual
+'
+
+test_done
-- 
2.22.0.rc1.539.g7bfcdfe86d
Previous: Jeff KingNext: Johannes Schindelin
Message 22 of 30 in “Abort (core dumped)”
  1. Alejandro SanchezMay 20, 2019
  2. Jeff KingMay 20, 2019
  3. 0/4 fix BUG() with "git am -i --resolved"Jeff King, May 20, 2019
  4. 1/4 am: simplify prompt response handlingJeff King, May 20, 2019
  5. 2/4 am: read interactive input from stdinJeff King, May 20, 2019
  6. 3/4 am: drop tty requirement for --interactiveJeff King, May 20, 2019
  7. Jeff KingMay 20, 2019
  8. Johannes SchindelinMay 23, 2019
  9. Jeff KingMay 24, 2019
  10. 0/2 prompt.c: split up git_prompt(), read from /dev/tty, not STDINÆvar Arnfjörð Bjarmason, Nov 2, 2021
  11. 1/2 prompt.c: split up the password and non-password handlingÆvar Arnfjörð Bjarmason, Nov 2, 2021
  12. Jeff KingNov 3, 2021
  13. Junio C HamanoNov 3, 2021
  14. 2/2 prompt.c: add and use a GIT_TEST_TERMINAL_PROMPT=trueÆvar Arnfjörð Bjarmason, Nov 2, 2021
  15. Jeff KingNov 3, 2021
  16. Ævar Arnfjörð BjarmasonNov 3, 2021
  17. Jeff KingNov 4, 2021
  18. Junio C HamanoNov 3, 2021
  19. Johannes SchindelinNov 4, 2021
  20. Jeff KingNov 4, 2021
  21. Jeff KingNov 4, 2021
  22. 4/4 am: fix --interactive HEAD tree resolutionJeff King, May 20, 2019
  23. Johannes SchindelinMay 23, 2019
  24. Jeff KingMay 24, 2019
  25. 4/4 am: fix --interactive HEAD tree resolutionJeff King, May 24, 2019
  26. Johannes SchindelinMay 28, 2019
  27. Jeff KingMay 28, 2019
  28. Johannes SchindelinMay 29, 2019
  29. Alejandro SanchezSep 26, 2019
  30. Jeff KingSep 26, 2019

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