Subject: [PATCH] commit: switch core.commentChar if it's found in existing commit

From: Nguyễn Thái Ngọc Duy <[email-masked]>
Date: Fri, 16 May 2014 17:59:42 +0700

If we need to use core.commentChar and it's already in the prepared
message, find another char among a small subset. This should stop
surprises because git strips some lines unexpectedly. Of course if
candicate characters happen to be all out, this change does not help.

Signed-off-by: Nguyễn Thái Ngọc Duy <[email-masked]>
---
 On Fri, May 16, 2014 at 5:28 PM, Duy Nguyen <[email-masked]> wrote:
 > But maybe git should detect that the
 > current commit message has leading '#' and automatically switch to
 > another character..

 Something like this. Lightly tested.. I know there's a small bug..

 builtin/commit.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/builtin/commit.c b/builtin/commit.c
index 6ab4605..70ceb61 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -593,6 +593,32 @@ static char *cut_ident_timestamp_part(char *string)
 	return ket;
 }
 
+static void adjust_comment_line_char(const struct strbuf *sb)
+{
+	char candidates[] = " !@#$%^&|:;~";
+	char *candidate;
+	const char *p;
+	if (!sb->len)
+		return;
+	candidates[0] = comment_line_char;
+	p = sb->buf;
+	do {
+		candidate = strchr(candidates, *p);
+		if (candidate)
+			*candidate = ' ';
+		p = strchrnul(p, '\n');
+		if (*p)
+			p++;
+	} while (*p);
+	if (strchr(candidates, comment_line_char)) {
+		p = candidates;
+		while (*p && *p == ' ')
+			p++;
+		if (*p)
+			comment_line_char = *p;
+	}
+}
+
 static int prepare_to_commit(const char *index_file, const char *prefix,
 			     struct commit *current_head,
 			     struct wt_status *s,
@@ -748,6 +774,9 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	if (fwrite(sb.buf, 1, sb.len, s->fp) < sb.len)
 		die_errno(_("could not write commit template"));
 
+	if (use_editor && include_status)
+		adjust_comment_line_char(&sb);
+
 	strbuf_release(&sb);
 
 	/* This checks if committer ident is explicitly given */
-- 
1.9.1.346.ga2b5940