string.c (struct mapping_buffer): Use FLEX_ARY_LEN

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61811 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

string.c

@@ -6384,7 +6384,7 @@ typedef struct mapping_buffer {
     size_t capa;
     size_t used;
     struct mapping_buffer *next;
-    OnigUChar space[1];
+    OnigUChar space[FLEX_ARY_LEN];
 } mapping_buffer;
 
 static VALUE
@@ -6410,7 +6410,7 @@ rb_str_casemap(VALUE source, OnigCaseFoldType *flags, rb_encoding *enc)
 	if (CASEMAP_DEBUG) {
 	    fprintf(stderr, "Buffer allocation, capa is %"PRIuSIZE"\n", capa); /* for tuning */
 	}
-	current_buffer->next = xmalloc(offsetof(mapping_buffer, space) + capa);
+	current_buffer->next = xmalloc(sizeof(mapping_buffer) + capa);
 	current_buffer = current_buffer->next;
 	current_buffer->next = NULL;
 	current_buffer->capa = capa;