commit-reach(repo_get_merge_bases): pass on "missing commits" errors

The `merge_bases_many()` function was just taught to indicate parsing
errors, and now the `repo_get_merge_bases()` function (which is also
surfaced via the `repo_get_merge_bases()` macro) is aware of that, too.

Naturally, there are a lot of callers that need to be adjusted now, too.

Next step: adjust the callers of `get_octopus_merge_bases()`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

5 files changed, 28 insertions, 20 deletions

diff --git a/builtin/log.c b/builtin/log.c
index 0631922886..b7147f893b 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -1704,11 +1704,11 @@ static struct commit *get_base_commit(const char *base_commit,
 	 */
 	while (rev_nr > 1) {
 		for (i = 0; i < rev_nr / 2; i++) {
-			struct commit_list *merge_base;
-			merge_base = repo_get_merge_bases(the_repository,
-							  rev[2 * i],
-							  rev[2 * i + 1]);
-			if (!merge_base || merge_base->next) {
+			struct commit_list *merge_base = NULL;
+			if (repo_get_merge_bases(the_repository,
+						 rev[2 * i],
+						 rev[2 * i + 1], &merge_base) < 0 ||
+			    !merge_base || merge_base->next) {
 				if (die_on_failure) {
 					die(_("failed to find exact merge base"));
 				} else {
diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
index 3bdec53fbe..8a460d5529 100644
--- a/builtin/merge-tree.c
+++ b/builtin/merge-tree.c
@@ -462,8 +462,9 @@ static int real_merge(struct merge_tree_options *o,
 		 * Get the merge bases, in reverse order; see comment above
 		 * merge_incore_recursive in merge-ort.h
 		 */
-		merge_bases = repo_get_merge_bases(the_repository, parent1,
-						   parent2);
+		if (repo_get_merge_bases(the_repository, parent1,
+					 parent2, &merge_bases) < 0)
+			exit(128);
 		if (!merge_bases && !o->allow_unrelated_histories)
 			die(_("refusing to merge unrelated histories"));
 		merge_bases = reverse_commit_list(merge_bases);
diff --git a/builtin/merge.c b/builtin/merge.c
index 8f819781cc..7c0189fb8f 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -1514,10 +1514,13 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 
 	if (!remoteheads)
 		; /* already up-to-date */
-	else if (!remoteheads->next)
-		common = repo_get_merge_bases(the_repository, head_commit,
-					      remoteheads->item);
-	else {
+	else if (!remoteheads->next) {
+		if (repo_get_merge_bases(the_repository, head_commit,
+					 remoteheads->item, &common) < 0) {
+			ret = 2;
+			goto done;
+		}
+	} else {
 		struct commit_list *list = remoteheads;
 		commit_list_insert(head_commit, &list);
 		common = get_octopus_merge_bases(list);
@@ -1627,7 +1630,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		struct commit_list *j;
 
 		for (j = remoteheads; j; j = j->next) {
-			struct commit_list *common_one;
+			struct commit_list *common_one = NULL;
 			struct commit *common_item;
 
 			/*
@@ -1635,9 +1638,10 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			 * merge_bases again, otherwise "git merge HEAD^
 			 * HEAD^^" would be missed.
 			 */
-			common_one = repo_get_merge_bases(the_repository,
-							  head_commit,
-							  j->item);
+			if (repo_get_merge_bases(the_repository, head_commit,
+						 j->item, &common_one) < 0)
+				exit(128);
+
 			common_item = common_one->item;
 			free_commit_list(common_one);
 			if (!oideq(&common_item->object.oid, &j->item->object.oid)) {
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 5b086f651a..a171e53c5e 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -867,7 +867,8 @@ static int can_fast_forward(struct commit *onto, struct commit *upstream,
 	if (!upstream)
 		goto done;
 
-	merge_bases = repo_get_merge_bases(the_repository, upstream, head);
+	if (repo_get_merge_bases(the_repository, upstream, head, &merge_bases) < 0)
+		exit(128);
 	if (!merge_bases || merge_bases->next)
 		goto done;
 
@@ -886,8 +887,9 @@ static void fill_branch_base(struct rebase_options *options,
 {
 	struct commit_list *merge_bases = NULL;
 
-	merge_bases = repo_get_merge_bases(the_repository, options->onto,
-					   options->orig_head);
+	if (repo_get_merge_bases(the_repository, options->onto,
+				 options->orig_head, &merge_bases) < 0)
+		exit(128);
 	if (!merge_bases || merge_bases->next)
 		oidcpy(branch_base, null_oid());
 	else
diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index d08987646a..181c703d4c 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -297,7 +297,7 @@ static int try_difference(const char *arg)
 		show_rev(NORMAL, &end_oid, end);
 		show_rev(symmetric ? NORMAL : REVERSED, &start_oid, start);
 		if (symmetric) {
-			struct commit_list *exclude;
+			struct commit_list *exclude = NULL;
 			struct commit *a, *b;
 			a = lookup_commit_reference(the_repository, &start_oid);
 			b = lookup_commit_reference(the_repository, &end_oid);
@@ -305,7 +305,8 @@ static int try_difference(const char *arg)
 				*dotdot = '.';
 				return 0;
 			}
-			exclude = repo_get_merge_bases(the_repository, a, b);
+			if (repo_get_merge_bases(the_repository, a, b, &exclude) < 0)
+				exit(128);
 			while (exclude) {
 				struct commit *commit = pop_commit(&exclude);
 				show_rev(REVERSED, &commit->object.oid, NULL);