texinfo 4.4 incompatibility with recent diffutils in pedantic mode

[Paul Eggert]

Here's a patch to texinfo 4.4 to fix a compatibility bug.  POSIX
1003.1-2001 says that standard programs like "diff" must reject
numeric options like -0.  If you set _POSIX2_VERSION=200112 in the
environment, recent diffutils versions enforce this restriction, which
causes "diff -u0" to fail since it combines "-u" and "-0".  "diff -U0"
is allowed, since it is equivalent to "diff -U 0".

Here is a patch, which should work with both old and new versions of
GNU diff.

2003-01-31  Paul Eggert  <address@hidden>

        * util/txitextest: Use "diff -U0" rather than "diff -u0", for
        compatibility with diffutils when run in pedantic mode with
        _POSIX2_VERSION=200112 in the environment.

--- util/txitextest     2003-01-31 08:26:23.000000000 -0800
+++ /tmp/txitextest     2003-01-31 22:28:56.019171434 -0800
@@ -63,6 +63,6 @@
     dvips $manual_base -o || exit 1
     mv $manual_base.ps old.$manual_base.ps
 
-    diff -u0 old.$manual_base.ps new.$manual_base.ps
+    diff -U0 old.$manual_base.ps new.$manual_base.ps
   fi
 done