Re: [PATCH 2/2] nedmalloc: work around overzealous GCC 6 warning

Johannes Schindelin [off-list ref] writes:

Hi Junio & René,

On Thu, 4 Aug 2016, Junio C Hamano wrote:

quoted

Let's try it this way.  How about this as a replacement?

I like it (with the if (s2) test intead of if (s1), of course). But please
record René as author, maybe mentioning myself with a "Diagnosed-by:"
line.

Hmph.  I cannot do that unilaterally without waiting for René to
respond, though.  In any case, with only header and footer changes,
here is what will appear in 'pu'.

Thanks.

-- >8 --
From: René Scharfe <redacted>
Date: Thu, 4 Aug 2016 23:56:54 +0200
Subject: [PATCH] nedmalloc: work around overzealous GCC 6 warning

With GCC 6, the strdup() function is declared with the "nonnull"
attribute, stating that it is not allowed to pass a NULL value as
parameter.

In nedmalloc()'s reimplementation of strdup(), Postel's Law is heeded
and NULL parameters are handled gracefully. GCC 6 complains about that
now because it thinks that NULL cannot be passed to strdup() anyway.

Because the callers in this project of strdup() must be prepared to
call any implementation of strdup() supplied by the platform, so it
is pointless to pretend that it is OK to call it with NULL.

Remove the conditional based on NULL-ness of the input; this
squelches the warning.

See https://gcc.gnu.org/gcc-6/porting_to.html for details.

Diagnosed-by: Johannes Schindelin [off-list ref]
Signed-off-by: René Scharfe <redacted>
Signed-off-by: Junio C Hamano <redacted>
---
 compat/nedmalloc/nedmalloc.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/compat/nedmalloc/nedmalloc.c b/compat/nedmalloc/nedmalloc.c
index 677d1b2..2d4ef59 100644
--- a/compat/nedmalloc/nedmalloc.c
+++ b/compat/nedmalloc/nedmalloc.c

@@ -955,12 +955,11 @@ void **nedpindependent_comalloc(nedpool *p, size_t elems, size_t *sizes, void **
  */
 char *strdup(const char *s1)
 {
-	char *s2 = 0;
-	if (s1) {
-		size_t len = strlen(s1) + 1;
-		s2 = malloc(len);
+	size_t len = strlen(s1) + 1;
+	char *s2 = malloc(len);
+
+	if (s2)
 		memcpy(s2, s1, len);
-	}
 	return s2;
 }
 #endif

-- 
2.9.2-766-gd7972a8