1 files changed, 82 insertions, 33 deletions

diff --git a/submodule.c b/submodule.c
index 7cb236b0a1..2d88c55589 100644
--- a/submodule.c
+++ b/submodule.c
@@ -280,9 +280,9 @@ void handle_ignore_submodules_arg(struct diff_options *diffopt,
 
 static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 		struct commit *left, struct commit *right,
-		int *fast_forward, int *fast_backward)
+		struct commit_list *merge_bases)
 {
-	struct commit_list *merge_bases, *list;
+	struct commit_list *list;
 
 	init_revisions(rev, NULL);
 	setup_revisions(0, NULL, rev, NULL);
@@ -291,13 +291,6 @@ static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 	left->object.flags |= SYMMETRIC_LEFT;
 	add_pending_object(rev, &left->object, path);
 	add_pending_object(rev, &right->object, path);
-	merge_bases = get_merge_bases(left, right);
-	if (merge_bases) {
-		if (merge_bases->item == left)
-			*fast_forward = 1;
-		else if (merge_bases->item == right)
-			*fast_backward = 1;
-	}
 	for (list = merge_bases; list; list = list->next) {
 		list->item->object.flags |= UNINTERESTING;
 		add_pending_object(rev, &list->item->object,
@@ -335,31 +328,23 @@ static void print_submodule_summary(struct rev_info *rev, FILE *f,
 	strbuf_release(&sb);
 }
 
-void show_submodule_summary(FILE *f, const char *path,
+/* Helper function to display the submodule header line prior to the full
+ * summary output. If it can locate the submodule objects directory it will
+ * attempt to lookup both the left and right commits and put them into the
+ * left and right pointers.
+ */
+static void show_submodule_header(FILE *f, const char *path,
 		const char *line_prefix,
 		struct object_id *one, struct object_id *two,
 		unsigned dirty_submodule, const char *meta,
-		const char *del, const char *add, const char *reset)
+		const char *reset,
+		struct commit **left, struct commit **right,
+		struct commit_list **merge_bases)
 {
-	struct rev_info rev;
-	struct commit *left = NULL, *right = NULL;
 	const char *message = NULL;
 	struct strbuf sb = STRBUF_INIT;
 	int fast_forward = 0, fast_backward = 0;
 
-	if (is_null_oid(two))
-		message = "(submodule deleted)";
-	else if (add_submodule_odb(path))
-		message = "(not initialized)";
-	else if (is_null_oid(one))
-		message = "(new submodule)";
-	else if (!(left = lookup_commit_reference(one->hash)) ||
-		 !(right = lookup_commit_reference(two->hash)))
-		message = "(commits not present)";
-	else if (prepare_submodule_summary(&rev, path, left, right,
-					   &fast_forward, &fast_backward))
-		message = "(revision walker failed)";
-
 	if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 		fprintf(f, "%sSubmodule %s contains untracked content\n",
 			line_prefix, path);
@@ -367,11 +352,46 @@ void show_submodule_summary(FILE *f, const char *path,
 		fprintf(f, "%sSubmodule %s contains modified content\n",
 			line_prefix, path);
 
+	if (is_null_oid(one))
+		message = "(new submodule)";
+	else if (is_null_oid(two))
+		message = "(submodule deleted)";
+
+	if (add_submodule_odb(path)) {
+		if (!message)
+			message = "(not initialized)";
+		goto output_header;
+	}
+
+	/*
+	 * Attempt to lookup the commit references, and determine if this is
+	 * a fast forward or fast backwards update.
+	 */
+	*left = lookup_commit_reference(one->hash);
+	*right = lookup_commit_reference(two->hash);
+
+	/*
+	 * Warn about missing commits in the submodule project, but only if
+	 * they aren't null.
+	 */
+	if ((!is_null_oid(one) && !*left) ||
+	     (!is_null_oid(two) && !*right))
+		message = "(commits not present)";
+
+	*merge_bases = get_merge_bases(*left, *right);
+	if (*merge_bases) {
+		if ((*merge_bases)->item == *left)
+			fast_forward = 1;
+		else if ((*merge_bases)->item == *right)
+			fast_backward = 1;
+	}
+
 	if (!oidcmp(one, two)) {
 		strbuf_release(&sb);
 		return;
 	}
 
+output_header:
 	strbuf_addf(&sb, "%s%sSubmodule %s %s..", line_prefix, meta, path,
 			find_unique_abbrev(one->hash, DEFAULT_ABBREV));
 	if (!fast_backward && !fast_forward)
@@ -383,16 +403,45 @@ void show_submodule_summary(FILE *f, const char *path,
 		strbuf_addf(&sb, "%s:%s\n", fast_backward ? " (rewind)" : "", reset);
 	fwrite(sb.buf, sb.len, 1, f);
 
-	if (!message) /* only NULL if we succeeded in setting up the walk */
-		print_submodule_summary(&rev, f, line_prefix, del, add, reset);
-	if (left)
-		clear_commit_marks(left, ~0);
-	if (right)
-		clear_commit_marks(right, ~0);
-
 	strbuf_release(&sb);
 }
 
+void show_submodule_summary(FILE *f, const char *path,
+		const char *line_prefix,
+		struct object_id *one, struct object_id *two,
+		unsigned dirty_submodule, const char *meta,
+		const char *del, const char *add, const char *reset)
+{
+	struct rev_info rev;
+	struct commit *left = NULL, *right = NULL;
+	struct commit_list *merge_bases = NULL;
+
+	show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
+			      meta, reset, &left, &right, &merge_bases);
+
+	/*
+	 * If we don't have both a left and a right pointer, there is no
+	 * reason to try and display a summary. The header line should contain
+	 * all the information the user needs.
+	 */
+	if (!left || !right)
+		goto out;
+
+	/* Treat revision walker failure the same as missing commits */
+	if (prepare_submodule_summary(&rev, path, left, right, merge_bases)) {
+		fprintf(f, "%s(revision walker failed)\n", line_prefix);
+		goto out;
+	}
+
+	print_submodule_summary(&rev, f, line_prefix, del, add, reset);
+
+out:
+	if (merge_bases)
+		free_commit_list(merge_bases);
+	clear_commit_marks(left, ~0);
+	clear_commit_marks(right, ~0);
+}
+
 void set_config_fetch_recurse_submodules(int value)
 {
 	config_fetch_recurse_submodules = value;