diff --git a/ChangeLog b/ChangeLog
index 56dd36565c..f37abc8999 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Thu Jul  8 15:47:34 2010  NARUSE, Yui  <naruse@ruby-lang.org>
+
+        * string.c (rb_str_conv_enc_opts): fix infinite loop because
+          of ISO-2022-JP conversion with empty string.
+          patched by Brian Buchanan [ruby-core:31107]
+
 Wed Jul  7 10:26:20 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* missing/close.c: ignore ECONNRESET.
diff --git a/string.c b/string.c
index 8cfbb56bdf..1b06370bb7 100644
--- a/string.c
+++ b/string.c
@@ -513,7 +513,7 @@ rb_str_conv_enc_opts(VALUE str, rb_encoding *from, rb_encoding *to, int ecflags,
     switch (ret) {
       case econv_destination_buffer_full:
 	/* destination buffer short */
-	len *= 2;
+	len = len < 2 ? 2 : len * 2;
 	rb_str_resize(newstr, len);
 	goto retry;