bison "make dist" failure if gzip doesn't support --rsyncable

[Paul Eggert]

My "gzip" (latest Debian stable) doesn't support --rsyncable, so I
installed this:

2004-04-28  Paul Eggert  <address@hidden>

        * Makefile.maint (GZIP_ENV): Don't use --rsyncable if gzip doesn't
        support it.  (The latest stable gzip doesn't.)

Index: Makefile.maint
===================================================================
RCS file: /cvsroot/bison/bison/Makefile.maint,v
retrieving revision 1.15
diff -p -u -r1.15 Makefile.maint
--- Makefile.maint      25 Aug 2003 18:47:36 -0000      1.15
+++ Makefile.maint      28 Apr 2004 19:46:33 -0000
@@ -2,7 +2,7 @@
 # This Makefile fragment is shared between the coreutils,
 # CPPI, Bison, and Autoconf.
 
-## Copyright (C) 2001-2003 Free Software Foundation, Inc.
+## Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
 ##
 ## This program is free software; you can redistribute it and/or modify
 ## it under the terms of the GNU General Public License as published by
@@ -24,7 +24,12 @@
 ME := Makefile.maint
 
 # Do not save the original name or timestamp in the .tar.gz file.
-GZIP_ENV = '--no-name --best --rsyncable'
+GZIP_ENV = \
+  "--no-name --best$$( \
+    case $$(gzip --help) in \
+    (*--rsyncable*) echo ' --rsyncable';; \
+    esac \
+  )"
 
 CVS = cvs