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diff: remove ternary operator evaluating always to true

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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 <stefanbeller@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Stefan Beller 2013-08-08 20:31:44 +02:00 committed by Junio C Hamano
parent 64948ad775
commit c189c4f2c4
1 changed files with 2 additions and 2 deletions
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4
diff.c
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@ -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;