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-rw-r--r--merge-recursive.c9
-rw-r--r--submodule.c161
-rw-r--r--submodule.h2
-rwxr-xr-xt/t7405-submodule-merge.sh128
4 files changed, 291 insertions, 9 deletions
diff --git a/merge-recursive.c b/merge-recursive.c
index 856e98c..4dcf417 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 61cb6e2..dcb4b5d 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 6fd3bb4..b0a571c 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 4a7b893..6ec559d 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' '