From fa042f65784c3b2aaae38fbb8ea4dc0cfcabc249 Mon Sep 17 00:00:00 2001
From: Doug Coleman <doug.coleman@gmail.com>
Date: Sun, 31 Jan 2010 16:29:20 -0600
Subject: [PATCH] Make sure we're not reading 0 bits in the lzw decompression
 loop -- this causes a hang

---
 basis/compression/lzw/lzw.factor | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/basis/compression/lzw/lzw.factor b/basis/compression/lzw/lzw.factor
index e017636009..340e455291 100644
--- a/basis/compression/lzw/lzw.factor
+++ b/basis/compression/lzw/lzw.factor
@@ -26,9 +26,11 @@ TUPLE: gif-lzw < lzw ;
     dup end-of-information-code>> 1 + initial-uncompress-table >>table
     dup initial-code-size>> >>code-size ;
 
+ERROR: code-size-zero ;
+
 : <lzw-uncompress> ( input code-size class -- obj )
     new
-        swap >>code-size
+        swap [ code-size-zero ] when-zero >>code-size
         dup code-size>> >>initial-code-size
         dup code-size>> 1 - 2^ >>clear-code
         dup clear-code>> 1 + >>end-of-information-code