@matheusbsbs / matheus-bagliano / commits / 40d71940b6

builtin/merge.c: fix a bug with trivial merges

If read_tree_trivial() succeeds and produces a tree that is already in the object store, then the index is not written to disk, leaving it out-of-sync with both HEAD and the working tree. In order to write the index back out to disk after a merge, write_index_locked() needs to be called. For most merge strategies, this is done from try_merge_strategy(). For fast forward updates, this is done from checkout_fast_forward(). When trivial merges work, the call to write_index_locked() is buried a little deeper: merge_trivial() -> write_tree_trivial() -> write_cache_as_tree() -> write_index_as_tree() -> write_locked_index() However, it is only called when !cache_tree_fully_valid(), which is how this bug is triggered. But that also shows why this bug doesn't affect any other merge strategies or cases. Add a direct call to write_index_locked() from merge_trivial() to fix this issue. Since the indirect call to write_locked_index() was conditional on cache_tree_fully_valid(), it won't be written twice. Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Elijah Newren committed Apr 9, 2016 at 23:13 UTC 40d71940b6a0dadb7873cce614992f1d71fcdfbd

2 files changed +9 -1

builtin/merge.c

@@ -822,6 +822,14 @@ static int merge_trivial(struct commit *head, struct commit_list *remoteheads)

822 {

823 unsigned char result_tree[20], result_commit[20];

824 struct commit_list *parents, **pptr = &parents;

825 + static struct lock_file lock;

826 +

827 + hold_locked_index(&lock, 1);

828 + refresh_cache(REFRESH_QUIET);

829 + if (active_cache_changed &&

830 + write_locked_index(&the_index, &lock, COMMIT_LOCK))

831 + return error(_("Unable to write index."));

832 + rollback_lock_file(&lock);

833

834 write_tree_trivial(result_tree);

835 printf(_("Wonderful.\n"));

t/t7605-merge-resolve.sh

+1 -1

@@ -43,7 +43,7 @@ merge_c1_to_c2_cmds='

44 test_expect_success 'merge c1 to c2' "$merge_c1_to_c2_cmds"

46 -test_expect_failure 'merge c1 to c2, again' "$merge_c1_to_c2_cmds"

46 +test_expect_success 'merge c1 to c2, again' "$merge_c1_to_c2_cmds"

48 test_expect_success 'merge c2 to c3 (fails)' '

49 git reset --hard c2 &&