cocci: drop bogus xstrdup_or_null() rule

13092a91 (cocci: refactor common patterns to use xstrdup_or_null(),
2016-10-12) introduced a rule to rewrite this conditional call to
xstrdup(E) and an assignment to variable V:

    - if (E)
    -    V = xstrdup(E);

into an unconditional call to xstrdup_or_null(E) and an assignment
to variable V:

    + V = xstrdup_or_null(E);

which is utterly bogus.  The original code may already have an
acceptable value in V and the conditional assignment may be to
improve the value already in V with a copy of a better value E when
(and only when) E is not NULL.

The rewritten construct unconditionally discards the existing value
of V and replaces it with a copy of E, even when E is NULL, which
changes the meaning of the program.

By the way, if it were

	-if (E && !V)
	-	V = xstrdup(E);
	+V = xstrdup_or_null(E);

it would probably have been correct.  But there is no existing code
that would have been improved by such a rule, so let's just remove
the bogus one without replacing with the more specific one.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Junio C Hamano 2022-04-30 22:00:30 -07:00
Родитель 6cd33dceed
Коммит 08bdd3a185
1 изменённых файлов: 0 добавлений и 8 удалений

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@ -1,11 +1,3 @@
@@
expression E;
expression V;
@@
- if (E)
- V = xstrdup(E);
+ V = xstrdup_or_null(E);
@@
expression E;
@@