From 72251b7de6daf2cd7916e3aad46df0047e5a5d2b Mon Sep 17 00:00:00 2001 From: Brad King Date: Thu, 13 Oct 2011 08:59:04 -0400 Subject: [PATCH 1/2] submodule: Demonstrate known breakage during recursive merge Since commit 68d03e4a (Implement automatic fast-forward merge for submodules, 2010-07-07) we try to suggest submodule commits that resolve a conflict. Consider a true recursive merge case b---bc / \ / o X \ / \ c---cb in which the two heads themselves (bc,cb) had resolved a submodule conflict (i.e. reference different commits than their parents). The submodule merge search runs during the temporary merge of the two merge bases (b,c) and prints out a suggestion that is not meaningful to the user. Then during the main merge the submodule merge search runs again but dies with the message fatal: --ancestry-path given but there are no bottom commits while trying to enumerate candidates. Demonstrate this known breakage with a new test in t7405-submodule-merge covering the case. Signed-off-by: Brad King Signed-off-by: Junio C Hamano --- t/t7405-submodule-merge.sh | 51 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) diff --git a/t/t7405-submodule-merge.sh b/t/t7405-submodule-merge.sh index a8fb30b792..14da2e3654 100755 --- a/t/t7405-submodule-merge.sh +++ b/t/t7405-submodule-merge.sh @@ -228,4 +228,55 @@ test_expect_success 'merging with a modify/modify conflict between merge bases' git merge d ' +# canonical criss-cross history in top and submodule +test_expect_success 'setup for recursive merge with submodule' ' + mkdir merge-recursive && + (cd merge-recursive && + git init && + mkdir sub && + (cd sub && + git init && + test_commit a && + git checkout -b sub-b master && + test_commit b && + git checkout -b sub-c master && + test_commit c && + git checkout -b sub-bc sub-b && + git merge sub-c && + git checkout -b sub-cb sub-c && + git merge sub-b && + git checkout master) && + git add sub && + git commit -m a && + git checkout -b top-b master && + (cd sub && git checkout sub-b) && + git add sub && + git commit -m b && + git checkout -b top-c master && + (cd sub && git checkout sub-c) && + git add sub && + git commit -m c && + git checkout -b top-bc top-b && + git merge -s ours --no-commit top-c && + (cd sub && git checkout sub-bc) && + git add sub && + git commit -m bc && + git checkout -b top-cb top-c && + git merge -s ours --no-commit top-b && + (cd sub && git checkout sub-cb) && + git add sub && + git commit -m cb) +' + +# merge should leave submodule unmerged in index +test_expect_failure 'recursive merge with submodule' ' + (cd merge-recursive && + test_must_fail git merge top-bc && + echo "160000 $(git rev-parse top-cb:sub) 2 sub" > expect2 && + echo "160000 $(git rev-parse top-bc:sub) 3 sub" > expect3 && + git ls-files -u > actual && + grep "$(cat expect2)" actual > /dev/null && + grep "$(cat expect3)" actual > /dev/null) +' + test_done From 80988783c8c417c5e914256b43ed3604cc8fa4c3 Mon Sep 17 00:00:00 2001 From: Brad King Date: Thu, 13 Oct 2011 08:59:05 -0400 Subject: [PATCH 2/2] submodule: Search for merges only at end of recursive merge The submodule merge search is not useful during virtual merges because the results cannot be used automatically. Furthermore any suggestions made by the search may apply to commits different than HEAD:sub and MERGE_HEAD:sub, thus confusing the user. Skip searching for submodule merges during a virtual merge such as that between B and C while merging the heads of: B---BC / \ / A X \ / \ C---CB Run the search only when the recursion level is zero (!o->call_depth). This fixes known breakage tested in t7405-submodule-merge. Signed-off-by: Brad King Signed-off-by: Junio C Hamano --- merge-recursive.c | 6 ++++-- submodule.c | 6 +++++- submodule.h | 2 +- t/t7405-submodule-merge.sh | 2 +- 4 files changed, 11 insertions(+), 5 deletions(-) diff --git a/merge-recursive.c b/merge-recursive.c index c34a4f148b..cc664c39b6 100644 --- a/merge-recursive.c +++ b/merge-recursive.c @@ -946,8 +946,10 @@ static struct merge_file_info merge_file_1(struct merge_options *o, free(result_buf.ptr); result.clean = (merge_status == 0); } else if (S_ISGITLINK(a->mode)) { - result.clean = merge_submodule(result.sha, one->path, one->sha1, - a->sha1, b->sha1); + result.clean = merge_submodule(result.sha, + one->path, one->sha1, + a->sha1, b->sha1, + !o->call_depth); } else if (S_ISLNK(a->mode)) { hashcpy(result.sha, a->sha1); diff --git a/submodule.c b/submodule.c index 0b709bc291..0fd10a0fdb 100644 --- a/submodule.c +++ b/submodule.c @@ -794,7 +794,7 @@ static void print_commit(struct commit *commit) int merge_submodule(unsigned char result[20], const char *path, const unsigned char base[20], const unsigned char a[20], - const unsigned char b[20]) + const unsigned char b[20], int search) { struct commit *commit_base, *commit_a, *commit_b; int parent_count; @@ -849,6 +849,10 @@ int merge_submodule(unsigned char result[20], const char *path, * user needs to confirm the resolution. */ + /* Skip the search if makes no sense to the calling context. */ + if (!search) + return 0; + /* find commit which merges them */ parent_count = find_first_merges(&merges, path, commit_a, commit_b); switch (parent_count) { diff --git a/submodule.h b/submodule.h index 799c22d6c6..80e04f3c8c 100644 --- a/submodule.h +++ b/submodule.h @@ -28,7 +28,7 @@ int fetch_populated_submodules(int num_options, const char **options, int quiet); unsigned is_submodule_modified(const char *path, int ignore_untracked); int merge_submodule(unsigned char result[20], const char *path, const unsigned char base[20], - const unsigned char a[20], const unsigned char b[20]); + const unsigned char a[20], const unsigned char b[20], int search); int check_submodule_needs_pushing(unsigned char new_sha1[20], const char *remotes_name); #endif diff --git a/t/t7405-submodule-merge.sh b/t/t7405-submodule-merge.sh index 14da2e3654..0d5b42a25b 100755 --- a/t/t7405-submodule-merge.sh +++ b/t/t7405-submodule-merge.sh @@ -269,7 +269,7 @@ test_expect_success 'setup for recursive merge with submodule' ' ' # merge should leave submodule unmerged in index -test_expect_failure 'recursive merge with submodule' ' +test_expect_success 'recursive merge with submodule' ' (cd merge-recursive && test_must_fail git merge top-bc && echo "160000 $(git rev-parse top-cb:sub) 2 sub" > expect2 &&