emit_line(): don't emit an empty <SET><RESET> followed by a newline

When emit_line() is called with an empty line (but non-zero length, as we
send line terminating LF or CRLF to the function), it used to emit
<SET><RESET> followed by a newline.  Stop the wastefulness.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 7 insertions, 6 deletions

diff --git a/diff.c b/diff.c
index 0d7f5ea4a..108c7d764 100644
--- a/diff.c
+++ b/diff.c
@@ -295,12 +295,13 @@ static void emit_line_0(FILE *file, const char *set, const char *reset,
 		nofirst = 0;
 	}
 
-	fputs(set, file);
-
-	if (!nofirst)
-		fputc(first, file);
-	fwrite(line, len, 1, file);
-	fputs(reset, file);
+	if (len || !nofirst) {
+		fputs(set, file);
+		if (!nofirst)
+			fputc(first, file);
+		fwrite(line, len, 1, file);
+		fputs(reset, file);
+	}
 	if (has_trailing_carriage_return)
 		fputc('\r', file);
 	if (has_trailing_newline)