Subject: Re: [PATCH v2 ] commit -v: strip diffs and submodule shortlogs from the commit message

From: Junio C Hamano <[email-masked]>
Date: Tue, 19 Nov 2013 11:42:35 -0800

Junio C Hamano <[email-masked]> writes:

> Jens Lehmann <[email-masked]> writes:
>
>> diff --git a/wt-status.h b/wt-status.h
>> index 6c29e6f..cd2709f 100644
>> --- a/wt-status.h
>> +++ b/wt-status.h
>> @@ -91,6 +91,8 @@ struct wt_status_state {
>>  	unsigned char cherry_pick_head_sha1[20];
>>  };
>>
>> +const char wt_status_diff_divider[];
>
> This gives me:
>
> ./wt-status.h:94:12: error: array 'wt_status_diff_divider' assumed to have one element [-Werror]
> cc1: all warnings being treated as errors
>
> which is a bit unfortunate.
>
> Regardless of that, from the API design standpoint, I think it may
> be much better not to expose this particular implementation element
> (i.e. the array) to the caller, but instead to export a helper
> function that takes a pointer to a piece of memory and let callers
> ask an "I have this line---is it the status cut mark?" question.

That is, something like this, perhaps.

 builtin/commit.c          |  9 +++------
 t/t7507-commit-verbose.sh | 15 ++++++++++++++-
 wt-status.c               | 15 +++++++++++++++
 wt-status.h               |  1 +
 4 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/builtin/commit.c b/builtin/commit.c
index 6ab4605..fedb45a 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1505,7 +1505,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	struct strbuf sb = STRBUF_INIT;
 	struct strbuf author_ident = STRBUF_INIT;
 	const char *index_file, *reflog_msg;
-	char *nl, *p;
+	char *nl;
 	unsigned char sha1[20];
 	struct ref_lock *ref_lock;
 	struct commit_list *parents = NULL, **pptr = &parents;
@@ -1601,11 +1601,8 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	}
 
 	/* Truncate the message just before the diff, if any. */
-	if (verbose) {
-		p = strstr(sb.buf, "\ndiff --git ");
-		if (p != NULL)
-			strbuf_setlen(&sb, p - sb.buf + 1);
-	}
+	if (verbose)
+		wt_status_truncate_message_at_cut_line(&sb);
 
 	if (cleanup_mode != CLEANUP_NONE)
 		stripspace(&sb, cleanup_mode == CLEANUP_ALL);
diff --git a/t/t7507-commit-verbose.sh b/t/t7507-commit-verbose.sh
index da5bd3b..09c1150 100755
--- a/t/t7507-commit-verbose.sh
+++ b/t/t7507-commit-verbose.sh
@@ -65,9 +65,22 @@ test_expect_success 'diff in message is retained without -v' '
 	check_message diff
 '
 
-test_expect_failure 'diff in message is retained with -v' '
+test_expect_success 'diff in message is retained with -v' '
 	git commit --amend -F diff -v &&
 	check_message diff
 '
 
+test_expect_success 'submodule log is stripped out too with -v' '
+	git config diff.submodule log &&
+	git submodule add ./. sub &&
+	git commit -m "sub added" &&
+	(
+		cd sub &&
+		echo "more" >>file &&
+		git commit -a -m "submodule commit"
+	) &&
+	GIT_EDITOR=cat test_must_fail git commit -a -v 2>err &&
+	test_i18ngrep "Aborting commit due to empty commit message." err
+'
+
 test_done
diff --git a/wt-status.c b/wt-status.c
index b4e44ba..492506a 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -16,6 +16,9 @@
 #include "column.h"
 #include "strbuf.h"
 
+static const char wt_status_cut_line[] =
+"# ------------------------ >8 ------------------------\n";
+
 static char default_wt_status_colors[][COLOR_MAXLEN] = {
 	GIT_COLOR_NORMAL, /* WT_STATUS_HEADER */
 	GIT_COLOR_GREEN,  /* WT_STATUS_UPDATED */
@@ -767,6 +770,15 @@ conclude:
 	status_printf_ln(s, GIT_COLOR_NORMAL, "");
 }
 
+void wt_status_truncate_message_at_cut_line(struct strbuf *buf)
+{
+	const char *p;
+
+	p = strstr(buf->buf, wt_status_cut_line);
+	if (p && (p == buf->buf || p[-1] == '\n'))
+		strbuf_setlen(buf, p - buf->buf);
+}
+
 static void wt_status_print_verbose(struct wt_status *s)
 {
 	struct rev_info rev;
@@ -791,6 +803,9 @@ static void wt_status_print_verbose(struct wt_status *s)
 	 */
 	if (s->fp != stdout)
 		rev.diffopt.use_color = 0;
+	fprintf(s->fp, wt_status_cut_line);
+	fprintf(s->fp, _("# Do not touch the line above.\n"));
+	fprintf(s->fp, _("# Everything below will be removed.\n"));
 	run_diff_index(&rev, 1);
 }
 
diff --git a/wt-status.h b/wt-status.h
index 6c29e6f..30a4812 100644
--- a/wt-status.h
+++ b/wt-status.h
@@ -91,6 +91,7 @@ struct wt_status_state {
 	unsigned char cherry_pick_head_sha1[20];
 };
 
+void wt_status_truncate_message_at_cut_line(struct strbuf *);
 void wt_status_prepare(struct wt_status *s);
 void wt_status_print(struct wt_status *s);
 void wt_status_collect(struct wt_status *s);