diff options
| -rw-r--r-- | merge-recursive.c | 9 | ||||
| -rw-r--r-- | submodule.c | 161 | ||||
| -rw-r--r-- | submodule.h | 2 | ||||
| -rwxr-xr-x | t/t7405-submodule-merge.sh | 128 |
4 files changed, 291 insertions, 9 deletions
diff --git a/merge-recursive.c b/merge-recursive.c index 856e98c083..4dcf417582 100644 --- a/merge-recursive.c +++ b/merge-recursive.c @@ -20,6 +20,7 @@ #include "attr.h" #include "merge-recursive.h" #include "dir.h" +#include "submodule.h" static struct tree *shift_tree_object(struct tree *one, struct tree *two, const char *subtree_shift) @@ -525,13 +526,15 @@ static void update_file_flags(struct merge_options *o, void *buf; unsigned long size; - if (S_ISGITLINK(mode)) + if (S_ISGITLINK(mode)) { /* * We may later decide to recursively descend into * the submodule directory and update its index * and/or work tree, but we do not do that now. */ + update_wd = 0; goto update_index; + } buf = read_sha1_file(sha, &type, &size); if (!buf) @@ -716,8 +719,8 @@ static struct merge_file_info merge_file(struct merge_options *o, free(result_buf.ptr); result.clean = (merge_status == 0); } else if (S_ISGITLINK(a->mode)) { - result.clean = 0; - hashcpy(result.sha, a->sha1); + result.clean = merge_submodule(result.sha, one->path, one->sha1, + a->sha1, b->sha1); } else if (S_ISLNK(a->mode)) { hashcpy(result.sha, a->sha1); diff --git a/submodule.c b/submodule.c index 61cb6e21dd..dcb4b5da71 100644 --- a/submodule.c +++ b/submodule.c @@ -6,6 +6,7 @@ #include "revision.h" #include "run-command.h" #include "diffcore.h" +#include "refs.h" static int add_submodule_odb(const char *path) { @@ -218,3 +219,163 @@ unsigned is_submodule_modified(const char *path, int ignore_untracked) strbuf_release(&buf); return dirty_submodule; } + +static int find_first_merges(struct object_array *result, const char *path, + struct commit *a, struct commit *b) +{ + int i, j; + struct object_array merges; + struct commit *commit; + int contains_another; + + char merged_revision[42]; + const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path", + "--all", merged_revision, NULL }; + struct rev_info revs; + struct setup_revision_opt rev_opts; + + memset(&merges, 0, sizeof(merges)); + memset(result, 0, sizeof(struct object_array)); + memset(&rev_opts, 0, sizeof(rev_opts)); + + /* get all revisions that merge commit a */ + snprintf(merged_revision, sizeof(merged_revision), "^%s", + sha1_to_hex(a->object.sha1)); + init_revisions(&revs, NULL); + rev_opts.submodule = path; + setup_revisions(sizeof(rev_args)/sizeof(char *)-1, rev_args, &revs, &rev_opts); + + /* save all revisions from the above list that contain b */ + if (prepare_revision_walk(&revs)) + die("revision walk setup failed"); + while ((commit = get_revision(&revs)) != NULL) { + struct object *o = &(commit->object); + if (in_merge_bases(b, &commit, 1)) + add_object_array(o, NULL, &merges); + } + + /* Now we've got all merges that contain a and b. Prune all + * merges that contain another found merge and save them in + * result. + */ + for (i = 0; i < merges.nr; i++) { + struct commit *m1 = (struct commit *) merges.objects[i].item; + + contains_another = 0; + for (j = 0; j < merges.nr; j++) { + struct commit *m2 = (struct commit *) merges.objects[j].item; + if (i != j && in_merge_bases(m2, &m1, 1)) { + contains_another = 1; + break; + } + } + + if (!contains_another) + add_object_array(merges.objects[i].item, + merges.objects[i].name, result); + } + + free(merges.objects); + return result->nr; +} + +static void print_commit(struct commit *commit) +{ + struct strbuf sb = STRBUF_INIT; + struct pretty_print_context ctx = {0}; + ctx.date_mode = DATE_NORMAL; + format_commit_message(commit, " %h: %m %s", &sb, &ctx); + fprintf(stderr, "%s\n", sb.buf); + strbuf_release(&sb); +} + +#define MERGE_WARNING(path, msg) \ + warning("Failed to merge submodule %s (%s)", path, msg); + +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]) +{ + struct commit *commit_base, *commit_a, *commit_b; + int parent_count; + struct object_array merges; + + int i; + + /* store a in result in case we fail */ + hashcpy(result, a); + + /* we can not handle deletion conflicts */ + if (is_null_sha1(base)) + return 0; + if (is_null_sha1(a)) + return 0; + if (is_null_sha1(b)) + return 0; + + if (add_submodule_odb(path)) { + MERGE_WARNING(path, "not checked out"); + return 0; + } + + if (!(commit_base = lookup_commit_reference(base)) || + !(commit_a = lookup_commit_reference(a)) || + !(commit_b = lookup_commit_reference(b))) { + MERGE_WARNING(path, "commits not present"); + return 0; + } + + /* check whether both changes are forward */ + if (!in_merge_bases(commit_base, &commit_a, 1) || + !in_merge_bases(commit_base, &commit_b, 1)) { + MERGE_WARNING(path, "commits don't follow merge-base"); + return 0; + } + + /* Case #1: a is contained in b or vice versa */ + if (in_merge_bases(commit_a, &commit_b, 1)) { + hashcpy(result, b); + return 1; + } + if (in_merge_bases(commit_b, &commit_a, 1)) { + hashcpy(result, a); + return 1; + } + + /* + * Case #2: There are one or more merges that contain a and b in + * the submodule. If there is only one, then present it as a + * suggestion to the user, but leave it marked unmerged so the + * user needs to confirm the resolution. + */ + + /* find commit which merges them */ + parent_count = find_first_merges(&merges, path, commit_a, commit_b); + switch (parent_count) { + case 0: + MERGE_WARNING(path, "merge following commits not found"); + break; + + case 1: + MERGE_WARNING(path, "not fast-forward"); + fprintf(stderr, "Found a possible merge resolution " + "for the submodule:\n"); + print_commit((struct commit *) merges.objects[0].item); + fprintf(stderr, + "If this is correct simply add it to the index " + "for example\n" + "by using:\n\n" + " git update-index --cacheinfo 160000 %s \"%s\"\n\n" + "which will accept this suggestion.\n", + sha1_to_hex(merges.objects[0].item->sha1), path); + break; + + default: + MERGE_WARNING(path, "multiple merges found"); + for (i = 0; i < merges.nr; i++) + print_commit((struct commit *) merges.objects[i].item); + } + + free(merges.objects); + return 0; +} diff --git a/submodule.h b/submodule.h index 6fd3bb4070..b0a571c7f0 100644 --- a/submodule.h +++ b/submodule.h @@ -9,5 +9,7 @@ void show_submodule_summary(FILE *f, const char *path, unsigned dirty_submodule, const char *del, const char *add, const char *reset); 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]); #endif diff --git a/t/t7405-submodule-merge.sh b/t/t7405-submodule-merge.sh index 4a7b8933f4..6ec559db0f 100755 --- a/t/t7405-submodule-merge.sh +++ b/t/t7405-submodule-merge.sh @@ -54,13 +54,129 @@ test_expect_success setup ' git merge -s ours a ' -test_expect_success 'merging with modify/modify conflict' ' +# History setup +# +# b +# / \ +# a d +# \ / +# c +# +# a in the main repository records to sub-a in the submodule and +# analogous b and c. d should be automatically found by merging c into +# b in the main repository. +test_expect_success 'setup for merge search' ' + mkdir merge-search && + cd merge-search && + git init && + mkdir sub && + (cd sub && + git init && + echo "file-a" > file-a && + git add file-a && + git commit -m "sub-a" && + git branch sub-a) && + git add sub && + git commit -m "a" && + git branch a && + + git checkout -b b && + (cd sub && + git checkout -b sub-b && + echo "file-b" > file-b && + git add file-b && + git commit -m "sub-b") && + git commit -a -m "b" && + + git checkout -b c a && + (cd sub && + git checkout -b sub-c sub-a && + echo "file-c" > file-c && + git add file-c && + git commit -m "sub-c") && + git commit -a -m "c" && + + git checkout -b d a && + (cd sub && + git checkout -b sub-d sub-b && + git merge sub-c) && + git commit -a -m "d" && + git branch test b && + cd .. +' + +test_expect_success 'merge with one side as a fast-forward of the other' ' + (cd merge-search && + git checkout -b test-forward b && + git merge d && + git ls-tree test-forward sub | cut -f1 | cut -f3 -d" " > actual && + (cd sub && + git rev-parse sub-d > ../expect) && + test_cmp actual expect) +' + +test_expect_success 'merging should conflict for non fast-forward' ' + (cd merge-search && + git checkout -b test-nonforward b && + (cd sub && + git rev-parse sub-d > ../expect) && + test_must_fail git merge c 2> actual && + grep $(cat expect) actual > /dev/null && + git reset --hard) +' + +test_expect_success 'merging should fail for ambiguous common parent' ' + cd merge-search && + git checkout -b test-ambiguous b && + (cd sub && + git checkout -b ambiguous sub-b && + git merge sub-c && + git rev-parse sub-d > ../expect1 && + git rev-parse ambiguous > ../expect2) && + test_must_fail git merge c 2> actual && + grep $(cat expect1) actual > /dev/null && + grep $(cat expect2) actual > /dev/null && + git reset --hard && + cd .. +' + +# in a situation like this +# +# submodule tree: +# +# sub-a --- sub-b --- sub-d +# +# main tree: +# +# e (sub-a) +# / +# bb (sub-b) +# \ +# f (sub-d) +# +# A merge between e and f should fail because one of the submodule +# commits (sub-a) does not descend from the submodule merge-base (sub-b). +# +test_expect_success 'merging should fail for changes that are backwards' ' + cd merge-search && + git checkout -b bb a && + (cd sub && + git checkout sub-b) && + git commit -a -m "bb" && + + git checkout -b e bb && + (cd sub && + git checkout sub-a) && + git commit -a -m "e" && + + git checkout -b f bb && + (cd sub && + git checkout sub-d) && + git commit -a -m "f" && - git checkout -b test1 a && - test_must_fail git merge b && - test -f .git/MERGE_MSG && - git diff && - test -n "$(git ls-files -u)" + git checkout -b test-backward e && + test_must_fail git merge f && + cd .. ' test_expect_success 'merging with a modify/modify conflict between merge bases' ' |