--- -	2013-11-25 22:10:59.694183795 -0700
+++ file.c	2013-11-25 22:10:03.076352889 -0700
@@ -2529,8 +2529,8 @@
	    || (rv < 0 && errno == ERANGE) /* quirky behavior of GPFS */
#endif
	) {
-	rb_str_modify_expand(v, size);
	size *= 2;
+	rb_str_modify_expand(v, size);
   }
   if (rv < 0) {
	rb_str_resize(v, 0);