From 08bdd3a1851cca1cebed0c5a26d1d4fcd5a73d16 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Sat, 30 Apr 2022 22:00:30 -0700 Subject: [PATCH] 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 --- contrib/coccinelle/xstrdup_or_null.cocci | 8 -------- 1 file changed, 8 deletions(-) diff --git a/contrib/coccinelle/xstrdup_or_null.cocci b/contrib/coccinelle/xstrdup_or_null.cocci index 8e05d1ca4b..9c1d2939b6 100644 --- a/contrib/coccinelle/xstrdup_or_null.cocci +++ b/contrib/coccinelle/xstrdup_or_null.cocci @@ -1,11 +1,3 @@ -@@ -expression E; -expression V; -@@ -- if (E) -- V = xstrdup(E); -+ V = xstrdup_or_null(E); - @@ expression E; @@