--- gcc/objc/hash.h	2018/04/24 18:10:18	1.1.1.2
+++ gcc/objc/hash.h	2018/04/24 18:20:20	1.1.1.4
@@ -27,11 +27,7 @@ the Free Software Foundation, 675 Mass A
 #ifndef __hash_INCLUDE_GNU
 #define __hash_INCLUDE_GNU
 
-#ifdef IN_GCC
-#include "gstddef.h"
-#else
-#include "stddef.h"
-#endif
+#include <stddef.h>
 
 /*
  * This data structure is used to hold items
@@ -193,7 +189,12 @@ compare_ptrs (const void *k1, const void
 static inline int 
 compare_strings (const void *k1, const void *k2)
 {
-  return !strcmp (k1, k2);
+  if (k1 == k2)
+    return 1;
+  else if (k1 == 0 || k2 == 0)
+    return 0;
+  else
+    return !strcmp (k1, k2);
 }