From c189c4f2c42083b329605fb7b0583b29b73da086 Mon Sep 17 00:00:00 2001 From: Stefan Beller Date: Thu, 8 Aug 2013 20:31:44 +0200 Subject: [PATCH] diff: remove ternary operator evaluating always to true The line being changed is deep inside the function builtin_diff. The variable name_b, which is used to evaluate the ternary expression must evaluate to true at that position, hence the replacement with just name_b. The name_b variable only occurs a few times in that lengthy function: As a parameter to the function itself: static void builtin_diff(const char *name_a, const char *name_b, ... The next occurrences are at: /* Never use a non-valid filename anywhere if at all possible */ name_a = DIFF_FILE_VALID(one) ? name_a : name_b; name_b = DIFF_FILE_VALID(two) ? name_b : name_a; a_one = quote_two(a_prefix, name_a + (*name_a == '/')); b_two = quote_two(b_prefix, name_b + (*name_b == '/')); In the last line of this block 'name_b' is dereferenced and compared to '/'. This would crash if name_b was NULL. Hence in the following code we can assume name_b being non-null. The next occurrence is just as a function argument, which doesn't change the memory, which name_b points to, so the assumption name_b being not null still holds: emit_rewrite_diff(name_a, name_b, one, two, textconv_one, textconv_two, o); The next occurrence would be the line of this patch. As name_b still must be not null, we can remove the ternary operator. Inside the emit_rewrite_diff function there is a also a line ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a); which was also simplified as there is also a dereference before the ternary operator. Signed-off-by: Stefan Beller Signed-off-by: Junio C Hamano --- diff.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/diff.c b/diff.c index 266112ca61..80f8439441 100644 --- a/diff.c +++ b/diff.c @@ -669,7 +669,7 @@ static void emit_rewrite_diff(const char *name_a, memset(&ecbdata, 0, sizeof(ecbdata)); ecbdata.color_diff = want_color(o->use_color); ecbdata.found_changesp = &o->found_changes; - ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a); + ecbdata.ws_rule = whitespace_rule(name_b); ecbdata.opt = o; if (ecbdata.ws_rule & WS_BLANK_AT_EOF) { mmfile_t mf1, mf2; @@ -2372,7 +2372,7 @@ static void builtin_diff(const char *name_a, ecbdata.label_path = lbl; ecbdata.color_diff = want_color(o->use_color); ecbdata.found_changesp = &o->found_changes; - ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a); + ecbdata.ws_rule = whitespace_rule(name_b); if (ecbdata.ws_rule & WS_BLANK_AT_EOF) check_blank_at_eof(&mf1, &mf2, &ecbdata); ecbdata.opt = o; -- 2.11.4.GIT