builtin/worktree: fix leaking derived branch names

There are several heuristics that git-worktree(1) uses to derive the
name of the newly created branch when not given explicitly. These
heuristics all allocate a new string, but we only end up freeing that
string in a subset of cases.

Fix the remaining cases where we didn't yet free the derived branch
names. While at it, also free `opt_track`, which is being populated via
an `OPT_PASSTHRU()`.

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

Author: pks-t

builtin/worktree.c

@@ -769,7 +769,7 @@ static int add(int ac, const char **av, const char *prefix)
 	char *branch_to_free = NULL;
 	char *new_branch_to_free = NULL;
 	const char *new_branch = NULL;
-	const char *opt_track = NULL;
+	char *opt_track = NULL;
 	const char *lock_reason = NULL;
 	int keep_locked = 0;
 	int used_new_branch_options;
@@ -846,7 +846,7 @@ static int add(int ac, const char **av, const char *prefix)
 	if (opts.orphan && !new_branch) {
 		int n;
 		const char *s = worktree_basename(path, &n);
-		new_branch = xstrndup(s, n);
+		new_branch = new_branch_to_free = xstrndup(s, n);
 	} else if (opts.orphan) {
 		; /* no-op */
 	} else if (opts.detach) {
@@ -875,7 +875,7 @@ static int add(int ac, const char **av, const char *prefix)
 			remote = unique_tracking_name(branch, &oid, NULL);
 			if (remote) {
 				new_branch = branch;
-				branch = remote;
+				branch = new_branch_to_free = remote;
 			}
 		}
 
@@ -923,6 +923,7 @@ static int add(int ac, const char **av, const char *prefix)
 
 	ret = add_worktree(path, branch, &opts);
 	free(path);
+	free(opt_track);
 	free(branch_to_free);
 	free(new_branch_to_free);
 	return ret;

t/t2400-worktree-add.sh

@@ -6,6 +6,7 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 TEST_CREATE_REPO_NO_TEMPLATE=1
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 . "$TEST_DIRECTORY"/lib-rebase.sh

t/t9902-completion.sh

@@ -16,6 +16,7 @@ test_untraceable=UnfortunatelyYes
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=master
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./lib-bash.sh
 
 complete ()