Re: [PATCH v2 04/18] unpack-trees: simplify pattern_list freeing

[Derrick Stolee <stolee@gmail.com>]

On 3/21/2020 1:59 PM, Elijah Newren via GitGitGadget wrote:
> From: Elijah Newren <newren@gmail.com>
> 
> commit e091228e17 ("sparse-checkout: update working directory
> in-process", 2019-11-21) allowed passing a pre-defined set of patterns
> to unpack_trees().  However, if o->pl was NULL, it would still read the
> existing patterns and use those.  If those patterns were read into a
> data structure that was allocated, naturally they needed to be free'd.
> However, despite the same function being responsible for knowing about
> both the allocation and the free'ing, the logic for tracking whether to
> free the pattern_list was hoisted to an outer function with an
> additional flag in unpack_trees_options.  Put the logic back in the
> relevant function and discard the now unnecessary flag.

Your approach here is much cleaner. Thanks!

> Signed-off-by: Elijah Newren <newren@gmail.com>
> ---
>  builtin/sparse-checkout.c | 1 -
>  unpack-trees.c            | 6 ++++--
>  unpack-trees.h            | 3 +--
>  3 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
> index 740da4b6d54..d102a9697fd 100644
> --- a/builtin/sparse-checkout.c
> +++ b/builtin/sparse-checkout.c
> @@ -122,7 +122,6 @@ static int update_working_directory(struct pattern_list *pl)
>  	o.dst_index = r->index;
>  	o.skip_sparse_checkout = 0;
>  	o.pl = pl;
> -	o.keep_pattern_list = !!pl;
>  
>  	resolve_undo_clear_index(r->index);
>  	setup_work_tree();
> diff --git a/unpack-trees.c b/unpack-trees.c
> index 3af2e126abf..d2863fa0310 100644
> --- a/unpack-trees.c
> +++ b/unpack-trees.c
> @@ -1503,6 +1503,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
>  	int i, ret;
>  	static struct cache_entry *dfc;
>  	struct pattern_list pl;
> +	int free_pattern_list = 0;
>  
>  	if (len > MAX_UNPACK_TREES)
>  		die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
> @@ -1519,6 +1520,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
>  		else
>  			o->pl = &pl;
>  		free(sparse);
> +		free_pattern_list = 1;
>  	}
>  
>  	memset(&o->result, 0, sizeof(o->result));
> @@ -1686,9 +1688,9 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
>  	o->src_index = NULL;
>  
>  done:
> -	trace_performance_leave("unpack_trees");
> -	if (!o->keep_pattern_list)
> +	if (free_pattern_list)
>  		clear_pattern_list(&pl);
> +	trace_performance_leave("unpack_trees");
>  	return ret;
>  
>  return_failed:
> diff --git a/unpack-trees.h b/unpack-trees.h
> index 6d7c7b6c2e0..d3516267f36 100644
> --- a/unpack-trees.h
> +++ b/unpack-trees.h
> @@ -58,8 +58,7 @@ struct unpack_trees_options {
>  		     quiet,
>  		     exiting_early,
>  		     show_all_errors,
> -		     dry_run,
> -		     keep_pattern_list;
> +		     dry_run;
>  	const char *prefix;
>  	int cache_bottom;
>  	struct dir_struct *dir;
>