# Pastebin DKz6LBUA
diff -r 276b2e484fdf -r 8e52e1e16d7c pypy/module/cpyext/include/pymem.h
--- a/pypy/module/cpyext/include/pymem.h        Tue Feb 27 22:59:35 2018 +0000
+++ b/pypy/module/cpyext/include/pymem.h        Wed Feb 28 16:10:36 2018 +0100
@@ -7,8 +7,8 @@
 extern "C" {
 #endif
 
-#define PyMem_MALLOC(n)                malloc((n) ? (n) : 1)
-#define PyMem_REALLOC(p, n)    realloc((p), (n) ? (n) : 1)
+#define PyMem_MALLOC(n)                malloc(((n) != 0) ? (n) : 1)
+#define PyMem_REALLOC(p, n)    realloc((p), ((n) != 0) ? (n) : 1)
 #define PyMem_FREE             free
 
 PyAPI_FUNC(void *) PyMem_Malloc(size_t);