Re: [GNU Autoconf 2.59c] diff might generate output for identical files

[Paul Eggert]

Ralf Menzel <address@hidden> writes:

> Here is the patch that I propose:

Thanks.  I installed the following somewhat-simpler patch.

2005-06-08  Paul Eggert  <address@hidden>

        * lib/autotest/general.m4 (AT_INIT): Don't accept Solaris 9's diff
        -u, since it outputs chatter if the input files are the same.
        Problem reported by Ralf Menzel.

--- general.m4.~1.183.~ 2005-06-07 23:48:32 -0700
+++ general.m4  2005-06-08 13:14:47 -0700
@@ -610,7 +610,8 @@ else
 fi
 
 # Use `diff -u' when possible.
-if diff -u "$at_devnull" "$at_devnull" >/dev/null 2>&1; then
+if at_diff=`diff -u "$at_devnull" "$at_devnull" 2>&1` && test -z "$at_diff"
+then
   at_diff='diff -u'
 else
   at_diff=diff