submodule--helper: fix "sm_path" and other "module_cb_list" leaks

Fix leaks in "struct module_cb_list" and the "struct module_cb" which
it contains, these fix leaks in e83e333 (submodule: port submodule
subcommand 'summary' from shell to C, 2020-08-13).

The "sm_path" should always have been a "char *", not a "const
char *", we always create it with xstrdup().

We can't mark any tests passing passing with SANITIZE=leak using
"TEST_PASSES_SANITIZE_LEAK=true" as a result of this change, but
"t7401-submodule-summary.sh" gets closer to passing as a result of
this change.

Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]>
Reviewed-by: Glen Choo <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: avar

builtin/submodule--helper.c

@@ -748,16 +748,34 @@ struct module_cb {
 	struct object_id oid_src;
 	struct object_id oid_dst;
 	char status;
-	const char *sm_path;
+	char *sm_path;
 };
 #define MODULE_CB_INIT { 0 }
 
+static void module_cb_release(struct module_cb *mcb)
+{
+	free(mcb->sm_path);
+}
+
 struct module_cb_list {
 	struct module_cb **entries;
 	int alloc, nr;
 };
 #define MODULE_CB_LIST_INIT { 0 }
 
+static void module_cb_list_release(struct module_cb_list *mcbl)
+{
+	int i;
+
+	for (i = 0; i < mcbl->nr; i++) {
+		struct module_cb *mcb = mcbl->entries[i];
+
+		module_cb_release(mcb);
+		free(mcb);
+	}
+	free(mcbl->entries);
+}
+
 struct summary_cb {
 	int argc;
 	const char **argv;
@@ -1101,6 +1119,7 @@ static int compute_summary_module_list(struct object_id *head_oid,
 cleanup:
 	strvec_clear(&diff_args);
 	release_revisions(&rev);
+	module_cb_list_release(&list);
 	return ret;
 }
 

t/t7401-submodule-summary.sh

@@ -17,6 +17,7 @@ This test script tries to verify the sanity of summary subcommand of git submodu
 # various reasons, one of them being that there are lots of commands taking place
 # outside of 'test_expect_success' block, which is no longer in good-style.
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 add_file () {