X-Git-Url: https://git.saurik.com/apple/libc.git/blobdiff_plain/9385eb3d10ebe5eb398c52040ec3dbfba9b0cdcf..2acb89982f71719aec26ca16705bd2c0400a9550:/stdlib/FreeBSD/reallocf.c

diff --git a/stdlib/FreeBSD/reallocf.c b/stdlib/FreeBSD/reallocf.c
index d502006..a85b5a3 100644
--- a/stdlib/FreeBSD/reallocf.c
+++ b/stdlib/FreeBSD/reallocf.c
@@ -25,7 +25,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: src/lib/libc/stdlib/reallocf.c,v 1.4 2002/03/22 21:53:10 obrien Exp $");
+__FBSDID("$FreeBSD$");
 
 #include <stdlib.h>
 
@@ -35,7 +35,14 @@ reallocf(void *ptr, size_t size)
 	void *nptr;
 
 	nptr = realloc(ptr, size);
-	if (!nptr && ptr)
+
+	/*
+	 * When the System V compatibility option (malloc "V" flag) is
+	 * in effect, realloc(ptr, 0) frees the memory and returns NULL.
+	 * So, to avoid double free, call free() only when size != 0.
+	 * realloc(ptr, 0) can't fail when ptr != NULL.
+	 */
+	if (!nptr && ptr && size != 0)
 		free(ptr);
 	return (nptr);
 }