Merge branch 'jc/conflict-hint' into cc/interpret-trailers-more

* jc/conflict-hint:
  merge & sequencer: turn "Conflicts:" hint into a comment
  builtin/commit.c: extract ignore_non_trailer() helper function
  merge & sequencer: unify codepaths that write "Conflicts:" hint
  builtin/merge.c: drop a parameter that is never used
  git-tag.txt: Add a missing hyphen to `-s`

1 files changed, 48 insertions, 26 deletions

diff --git a/builtin/commit.c b/builtin/commit.c
index 41f481bd03..80a618fe13 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -669,6 +669,52 @@ static void adjust_comment_line_char(const struct strbuf *sb)
 	comment_line_char = *p;
 }
 
+/*
+ * Inspect sb and determine the true "end" of the log message, in
+ * order to find where to put a new Signed-off-by: line.  Ignored are
+ * trailing comment lines and blank lines, and also the traditional
+ * "Conflicts:" block that is not commented out, so that we can use
+ * "git commit -s --amend" on an existing commit that forgot to remove
+ * it.
+ *
+ * Returns the number of bytes from the tail to ignore, to be fed as
+ * the second parameter to append_signoff().
+ */
+static int ignore_non_trailer(struct strbuf *sb)
+{
+	int boc = 0;
+	int bol = 0;
+	int in_old_conflicts_block = 0;
+
+	while (bol < sb->len) {
+		char *next_line;
+
+		if (!(next_line = memchr(sb->buf + bol, '\n', sb->len - bol)))
+			next_line = sb->buf + sb->len;
+		else
+			next_line++;
+
+		if (sb->buf[bol] == comment_line_char || sb->buf[bol] == '\n') {
+			/* is this the first of the run of comments? */
+			if (!boc)
+				boc = bol;
+			/* otherwise, it is just continuing */
+		} else if (starts_with(sb->buf + bol, "Conflicts:\n")) {
+			in_old_conflicts_block = 1;
+			if (!boc)
+				boc = bol;
+		} else if (in_old_conflicts_block && sb->buf[bol] == '\t') {
+			; /* a pathname in the conflicts block */
+		} else if (boc) {
+			/* the previous was not trailing comment */
+			boc = 0;
+			in_old_conflicts_block = 0;
+		}
+		bol = next_line - sb->buf;
+	}
+	return boc ? sb->len - boc : 0;
+}
+
 static int prepare_to_commit(const char *index_file, const char *prefix,
 			     struct commit *current_head,
 			     struct wt_status *s,
@@ -792,32 +838,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 	if (clean_message_contents)
 		stripspace(&sb, 0);
 
-	if (signoff) {
-		/*
-		 * See if we have a Conflicts: block at the end. If yes, count
-		 * its size, so we can ignore it.
-		 */
-		int ignore_footer = 0;
-		int i, eol, previous = 0;
-		const char *nl;
-
-		for (i = 0; i < sb.len; i++) {
-			nl = memchr(sb.buf + i, '\n', sb.len - i);
-			if (nl)
-				eol = nl - sb.buf;
-			else
-				eol = sb.len;
-			if (starts_with(sb.buf + previous, "\nConflicts:\n")) {
-				ignore_footer = sb.len - previous;
-				break;
-			}
-			while (i < eol)
-				i++;
-			previous = eol;
-		}
-
-		append_signoff(&sb, ignore_footer, 0);
-	}
+	if (signoff)
+		append_signoff(&sb, ignore_non_trailer(&sb), 0);
 
 	if (fwrite(sb.buf, 1, sb.len, s->fp) < sb.len)
 		die_errno(_("could not write commit template"));