Subject: [PATCH 05/19] diff.c: emit_line_0 can handle no color setting

From: Stefan Beller <[email-masked]>
Date: Sat, 13 May 2017 21:01:03 -0700

In a later patch, I want to propose an option to detect&color
moved lines in a diff, which cannot be done in a one-pass over
the diff. Instead we need to go over the whole diff twice,
because we cannot detect the first line of the two corresponding
lines (+ and -) that got moved.

So to prepare the diff machinery for two pass algorithms
(i.e. buffer it all up and then operate on the result),
move all emissions to places, such that the only emitting
function is emit_line_0.

In later patches we may pass lines that are not colored to
the central function emit_line_0, so we
need to emit the color only when it is non-NULL.

Signed-off-by: Stefan Beller <[email-masked]>
---
 diff.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/diff.c b/diff.c
index 381b572d76..48f0fb98dc 100644
--- a/diff.c
+++ b/diff.c
@@ -532,11 +532,13 @@ static void emit_line_0(struct diff_options *o, const char *set, const char *res
 		len--;
 
 	if (len || sign) {
-		fputs(set, file);
+		if (set)
+			fputs(set, file);
 		if (sign)
 			fputc(sign, file);
 		fwrite(line, len, 1, file);
-		fputs(reset, file);
+		if (reset)
+			fputs(reset, file);
 	}
 	if (has_trailing_carriage_return)
 		fputc('\r', file);
-- 
2.13.0.18.g183880de0a