I'm currently testing the following patch, which makes the message a
warning only (no exit status change).  Also, this should be warnx,
since errno is not relevant.  I intend to commit this if it works ok;
please let me know of any objections.

Index: gzip.c
===================================================================
RCS file: /cvsroot/src/usr.bin/gzip/gzip.c,v
retrieving revision 1.77
diff -u -r1.77 gzip.c
--- gzip.c	20 Sep 2005 05:12:15 -0000	1.77
+++ gzip.c	18 Nov 2005 12:38:03 -0000
@@ -639,8 +639,9 @@
 		 (int)(in_tot >> 24) & 0xff);
 	if (i != 8)
 		maybe_err("snprintf");
-	if (in_tot > 0xffffffff)
-		maybe_warn("input file size >= 4GB cannot be saved");
+	if (in_tot > 0xffffffff && qflag == 0)
+		/* Do not set exit status to 1. */
+		warn("input file size >= 4GB cannot be saved");
 	if (write(out, outbufp, i) != i) {
 		maybe_warn("write");
 		in_tot = -1;

-- 
        Greg Troxel <gdt@ir.bbn.com>