Re: [RFC/PATCH 05/17] diff.c: emit_line_0 can handle no color setting
From: Junio C Hamano <hidden>
Date: 2016-09-13 22:52:05
Stefan Beller [off-list ref] writes:
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.
Explained this way, a reader would find that this step is here before the underlying code is ready--we are not even buffering at this step yet. But that is OK. It used to be that passing "" as set/reset was the way to get a --no-color output. Now you can pass NULL instead of empty strings. That would be an alternative explanation why this is an acceptable change (as your later step probably has a good reason why it cannot pass "" instead of NULL).
quoted hunk
Signed-off-by: Stefan Beller <redacted> --- 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);