* unlzw.c (unlzw): Avoid integer overflow.
Aki Helin reported the segfault along with an input to trigger the bug.
Index: gzip-1.3.13/unlzw.c
===================================================================
--- gzip-1.3.13.orig/unlzw.c
+++ gzip-1.3.13/unlzw.c
@@ -244,7 +244,8 @@ int unlzw(in, out)
 	int  o;
 
     resetbuf:
-	e = insize-(o = (posbits>>3));
+        o = posbits >> 3;
+        e = o <= insize ? insize - o : 0;
 
 	for (i = 0 ; i < e ; ++i) {
 	    inbuf[i] = inbuf[i+o];