Re: [PATCH v10 00/21] Convert "git stash" to C builtin

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Thomas,

On Mon, 15 Oct 2018, Thomas Gummerer wrote:

>  2:  63f2e0e6f9 !  2:  2d45985676 strbuf.c: add `strbuf_join_argv()`
>     @@ -14,19 +14,17 @@
>       	strbuf_setlen(sb, sb->len + sb2->len);
>       }
>       
>     -+const char *strbuf_join_argv(struct strbuf *buf,
>     -+			     int argc, const char **argv, char delim)
>     ++void strbuf_join_argv(struct strbuf *buf,
>     ++		      int argc, const char **argv, char delim)

While the patch series does not use the return value, I have to ask
whether it would really be useful to change it to return `void`. I could
imagine that there may already be quite a few code paths that would love
to use strbuf_join_argv(), *and* would benefit from the `const char *`
return value.

In other words: just because the *current* patches do not make use of that
quite convenient return value does not mean that we should remove that
convenience.

>  7:  a2abd1b4bd !  8:  974dbaa492 stash: convert apply to builtin
>     @@ -370,18 +370,20 @@
>      +
>      +			if (diff_tree_binary(&out, &info->w_commit)) {
>      +				strbuf_release(&out);
>     -+				return -1;
>     ++				return error(_("Could not generate diff %s^!."),
>     ++					     oid_to_hex(&info->w_commit));

Please start the argument of an `error()` call with a lower-case letter.

>      +			}
>      +
>      +			ret = apply_cached(&out);
>      +			strbuf_release(&out);
>      +			if (ret)
>     -+				return -1;
>     ++				return error(_("Conflicts in index."
>     ++					       "Try without --index."));

Same here.

>      +
>      +			discard_cache();
>      +			read_cache();
>      +			if (write_cache_as_tree(&index_tree, 0, NULL))
>     -+				return -1;
>     ++				return error(_("Could not save index tree"));

And here.

> 15:  bd827be103 ! 15:  989db67e9a stash: convert create to builtin
>     @@ -119,7 +119,6 @@
>      +static int check_changes(struct pathspec ps, int include_untracked)
>      +{
>      +	int result;
>     -+	int ret = 0;

I was curious about this change, and could not find it in the
git-stash-v10 tag of https://github.com/ungps/git...

> 18:  1c501ad666 ! 18:  c90e30173a stash: convert save to builtin
>     @@ -72,8 +72,10 @@
>      +			     git_stash_helper_save_usage,
>      +			     PARSE_OPT_KEEP_DASHDASH);
>      +
>     -+	if (argc)
>     -+		stash_msg = (char*) strbuf_join_argv(&buf, argc, argv, ' ');
>     ++	if (argc) {
>     ++		strbuf_join_argv(&buf, argc, argv, ' ');
>     ++		stash_msg = buf.buf;
>     ++	}

Aha! So there *was* a user of that return value. I really would prefer a
non-void return value here.

> 19:  c4401b21db ! 19:  4360ea875d stash: convert `stash--helper.c` into `stash.c`
>     @@ -264,9 +320,9 @@
>      -	argc = parse_options(argc, argv, prefix, options,
>      -			     git_stash_helper_create_usage,
>      -			     0);
>     -+	/* Startinf with argv[1], since argv[0] is "create" */
>     -+	stash_msg = (char*) strbuf_join_argv(&stash_msg_buf, argc - 1,
>     -+					     ++argv, ' ');
>     ++	/* Starting with argv[1], since argv[0] is "create" */
>     ++	strbuf_join_argv(&stash_msg_buf, argc - 1, ++argv, ' ');
>     ++	stash_msg = stash_msg_buf.buf;

Again, I would strongly prefer the convenience of assigning the return
value directly, rather than having two lines.

>     @@ -375,10 +425,8 @@
>      +			 * they need to be immediately followed by a string
>      +			 * (i.e.`-m"foobar"` or `--message="foobar"`).
>      +			 */
>     -+			if ((strlen(argv[i]) > 2 &&
>     -+			     !strncmp(argv[i], "-m", 2)) ||
>     -+			    (strlen(argv[i]) > 10 &&
>     -+			     !strncmp(argv[i], "--message=", 10)))
>     ++			if (starts_with(argv[i], "-m") ||
>     ++			    starts_with(argv[i], "--message="))

Very nice.

> 20:  92dc11fd16 ! 20:  a384b05008 stash: optimize `get_untracked_files()` and `check_changes()`
>     @@ -52,7 +52,6 @@
>      +static int check_changes_tracked_files(struct pathspec ps)
>       {
>       	int result;
>     --	int ret = 0;

I also wonder about this change, in light of...

>       	struct rev_info rev;
>       	struct object_id dummy;
>      -	struct strbuf out = STRBUF_INIT;
>     @@ -99,8 +98,8 @@
>      -	if (!check_changes(ps, include_untracked)) {
>      +	if (!check_changes(ps, include_untracked, &untracked_files)) {
>       		ret = 1;

this here line. How does that work, if `ret` is removed? And why didn't
the `make DEVELOPER=1` complain about that unused `ret` variable before?

>     - 		*stash_msg = NULL;
>       		goto done;
>     + 	}
>      @@
>       		goto done;

The rest of the changes looks pretty sensible to me (indentation/wrapping
changes, mostly, with a couple of commit message/typo fixes thrown in).

Maybe you have a commit hash, or even better, a tag in a public Git
repository somewhere, so that Paul can pick it up more easily (and compare
the changes with his latest local branch)?

Thank you!
Dscho