builtin/merge-tree: fix leaking -X strategy options

The `-X` switch for git-merge-tree(1) will push each option into a local
`xopts` vector that we then end up parsing. The vector never gets freed
though, causing a memory leak. Plug it.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

builtin/merge-tree.c

@@ -533,6 +533,7 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 	int expected_remaining_argc;
 	int original_argc;
 	const char *merge_base = NULL;
+	int ret;
 
 	const char * const merge_tree_usage[] = {
 		N_("git merge-tree [--write-tree] [<options>] <branch1> <branch2>"),
@@ -625,7 +626,9 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 			strbuf_list_free(split);
 		}
 		strbuf_release(&buf);
-		return 0;
+
+		ret = 0;
+		goto out;
 	}
 
 	/* Figure out which mode to use */
@@ -664,7 +667,11 @@ int cmd_merge_tree(int argc, const char **argv, const char *prefix)
 
 	/* Do the relevant type of merge */
 	if (o.mode == MODE_REAL)
-		return real_merge(&o, merge_base, argv[0], argv[1], prefix);
+		ret = real_merge(&o, merge_base, argv[0], argv[1], prefix);
 	else
-		return trivial_merge(argv[0], argv[1], argv[2]);
+		ret = trivial_merge(argv[0], argv[1], argv[2]);
+
+out:
+	strvec_clear(&xopts);
+	return ret;
 }

t/t4301-merge-tree-write-tree.sh

@@ -2,6 +2,7 @@
 
 test_description='git merge-tree --write-tree'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # This test is ort-specific