Subject: Re: [PATCH v4 3/3] builtin/grep.c: walking tree instead of expanding index with --sparse

From: Junio C Hamano <[email-masked]>
Date: Fri, 02 Sep 2022 21:39:09 -0700

Shaoxuan Yuan <[email-masked]> writes:

> @@ -537,8 +534,20 @@ static int grep_cache(struct grep_opt *opt,
>  
>  		strbuf_setlen(&name, name_base_len);
>  		strbuf_addstr(&name, ce->name);
> +		if (S_ISSPARSEDIR(ce->ce_mode)) {
> +			enum object_type type;
> +			struct tree_desc tree;
> +			void *data;
> +			unsigned long size;
> +
> +			data = read_object_file(&ce->oid, &type, &size);
> +			init_tree_desc(&tree, data, size);
>  
> -		if (S_ISREG(ce->ce_mode) &&
> +			hit |= grep_tree(opt, pathspec, &tree, &name, 0, 0);
> +			strbuf_reset(&name);

Is this correct?

I would have expected that this would chomp to name_base_len, just
like what the code before this if/elseif cascade did.

There needs a test that is run with repo->submodule_prefix != NULL
to uncover issues like this, perhaps?

> +			strbuf_addstr(&name, ce->name);
> +			free(data);
> +		} else if (S_ISREG(ce->ce_mode) &&
>  		    match_pathspec(repo->index, pathspec, name.buf, name.len, 0, NULL,
>  				   S_ISDIR(ce->ce_mode) ||
>  				   S_ISGITLINK(ce->ce_mode))) {
> diff --git a/t/perf/p2000-sparse-operations.sh b/t/perf/p2000-sparse-operations.sh
> index fce8151d41..3242cfe91a 100755
> --- a/t/perf/p2000-sparse-operations.sh
> +++ b/t/perf/p2000-sparse-operations.sh
> @@ -124,5 +124,6 @@ test_perf_on_all git read-tree -mu HEAD
>  test_perf_on_all git checkout-index -f --all
>  test_perf_on_all git update-index --add --remove $SPARSE_CONE/a
>  test_perf_on_all "git rm -f $SPARSE_CONE/a && git checkout HEAD -- $SPARSE_CONE/a"
> +test_perf_on_all git grep --cached --sparse bogus -- "f2/f1/f1/*"
>  
>  test_done
> diff --git a/t/t1092-sparse-checkout-compatibility.sh b/t/t1092-sparse-checkout-compatibility.sh
> index 63becc3138..56e4614276 100755
> --- a/t/t1092-sparse-checkout-compatibility.sh
> +++ b/t/t1092-sparse-checkout-compatibility.sh
> @@ -1987,7 +1987,15 @@ test_expect_success 'grep is not expanded' '
>  
>  	# All files within the folder1/* pathspec are sparse,
>  	# so this command does not find any matches
> -	ensure_not_expanded ! grep a -- folder1/*
> +	ensure_not_expanded ! grep a -- folder1/* &&
> +
> +	# test out-of-cone pathspec with or without wildcard
> +	ensure_not_expanded grep --sparse --cached a -- "folder1/a" &&
> +	ensure_not_expanded grep --sparse --cached a -- "folder1/*" &&
> +
> +	# test in-cone pathspec with or without wildcard
> +	ensure_not_expanded grep --sparse --cached a -- "deep/a" &&
> +	ensure_not_expanded grep --sparse --cached a -- "deep/*"
>  '
>  
>  test_done