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 <>
 diff.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/diff.c b/diff.c
index b6a40ae..5d57130 100644
--- a/diff.c
+++ b/diff.c
@@ -473,11 +473,13 @@ static void emit_line_0(struct diff_options *o, const 
char *set, const char *res
        if (len || !nofirst) {
-               fputs(set, file);
+               if (set)
+                       fputs(set, file);
                if (!nofirst)
                        fputc(first, file);
                fwrite(line, len, 1, file);
-               fputs(reset, file);
+               if (reset)
+                       fputs(reset, file);
        if (has_trailing_carriage_return)
                fputc('\r', file);

Reply via email to