Returning NULL from mem_heap_alloc_block if requested block size is zero.

src/liballocator/mem-heap.h

@@ -88,14 +88,14 @@ extern void mem_heap_stats_reset_peak (void);
  */
 #define MEM_DEFINE_LOCAL_ARRAY(var_name, number, type) \
 { \
-  type *var_name = ((number > 0) \
-                    ? mem_heap_alloc_block ((number) * sizeof (type), MEM_HEAP_ALLOC_SHORT_TERM) \
-                    : NULL); \
+  size_t var_name ## ___size = (size_t) (number) * sizeof (type); \
+  type *var_name = mem_heap_alloc_block (var_name ## ___size, MEM_HEAP_ALLOC_SHORT_TERM); \
   \
-  if (var_name == NULL) \
+  if (number > 0 \
+      && var_name == NULL) \
   { \
     jerry_exit (ERR_OUT_OF_MEMORY); \
-  } \
+  }
 
 /**
  * Free the previously defined local array variable, freeing corresponding block on the heap,
@@ -104,8 +104,14 @@ extern void mem_heap_stats_reset_peak (void);
 #define MEM_FINALIZE_LOCAL_ARRAY(var_name) \
   if (var_name != NULL) \
   { \
+    JERRY_ASSERT (var_name ## ___size != 0); \
+    \
     mem_heap_free_block (var_name); \
   } \
+  else \
+  { \
+    JERRY_ASSERT (var_name ## ___size == 0); \
+  } \
 }
 
 /**