Re: [PATCH 1/4] branch: add branch_checked_out() helper

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 9, 2022, 23:47 UTC
Message-ID: <xmqq8rq5iel7.fsf@gitster.g>
In-Reply-To: <dbb7eae390c90d4b710f48d8875bd7db0409aea3.1654718942.git.gitgitgadget@gmail.com>

"Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com> writes:

Show 22 quoted lines

> +static void prepare_checked_out_branches(void)
> +{
> +	int i = 0;
> +	struct worktree **worktrees;
> +
> +	if (initialized_checked_out_branches)
> +		return;
> +	initialized_checked_out_branches = 1;
> +
> +	worktrees = get_worktrees();
> +
> +	while (worktrees[i]) {
> +		struct worktree *wt = worktrees[i++];
> +
> +		if (wt->is_bare)
> +			continue;
> +
> +		if (wt->head_ref)
> +			strmap_put(&current_checked_out_branches,
> +				   wt->head_ref,
> +				   xstrdup(wt->path));
> +	}

If two worktrees have by accident or by bug checked out the same branch, this strmap_put() will leak, as it overwrites the path to the worktree we found earlier with the branch checked out with the path to the worktree we just discovered with the same branch checked out. We could easily work it around by immediately freeing what comes back from strmap_put(), presumably. The resulting code

		if (wt->head_ref)
			free(strmap_put(...));

may look strange, though, especially because we will see more instances of strmap_put() in this loop in later steps.