The huft_build() function should return 2 if the input is invalid (such 

as all zero length codes) and 0 if the input is valid.  The zero length 

code check incorrectly returns 0 however causing gzip to segv on some 

invalid input cases.

Discovered & fixed by Tavis Ormandy.

http://bugs.gentoo.org/94584

--- inflate.c

+++ inflate.c

@@ -336,9 +336,9 @@ int huft_build(b, n, s, d, e, t, m)

   if (c[0] == n)                /* null input--all zero length codes */

   {

     *t = (struct huft *)NULL;

     *m = 0;

-    return 0;

+    return 2;

   }

   /* Find minimum and maximum length, bound *m by those */