Nest conditions for checking negative keys

Author: bbrtj

av.c

@@ -293,13 +293,12 @@ Perl_av_fetch(pTHX_ AV *av, SSize_t key, I32 lval)
     /* the cast from SSize_t to Size_t allows both (key < 0) and (key >= size)
      * to be tested as a single condition */
     if ((Size_t)key >= (Size_t)size) {
-        if (LIKELY(key < 0))
+        if (LIKELY(key < 0)) {
             key += size;
-        else
+            if (UNLIKELY(key < 0))
+                return NULL;
+        } else
             goto emptiness;
-
-        if (UNLIKELY(key < 0))
-            return NULL;
     }
 
     if (AvARRAY(av)[key])