Fix distcheck for Autoconf

[Ralf Wildenhues]

This patch gets the Autoconf package back into a state where, iff you
have re-autoreconf'ed your git checkout hard enough (as documented!),
distcheck again has a chance to pass.  Note that this patch does
nothing to improve consistency between actual checked-out version and
version string incorporated in various places.

I'll commit in a couple of days, given no objections.

Cheers,
Ralf

2007-11-05  Ralf Wildenhues  <address@hidden>

        Fix distcheck for Autoconf.
        * tests/Makefile.am ($(srcdir)/package.m4): Only update
        if contents have changed.

diff --git a/tests/Makefile.am b/tests/Makefile.am
index ed129fd..34f681d 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -44,8 +44,12 @@ $(srcdir)/package.m4: Makefile
          echo 'm4_define([AT_PACKAGE_VERSION],   [$(PACKAGE_VERSION)])'; \
          echo 'm4_define([AT_PACKAGE_STRING],    [$(PACKAGE_STRING)])'; \
          echo 'm4_define([AT_PACKAGE_BUGREPORT], [$(PACKAGE_BUGREPORT)])'; \
-       } >$(srcdir)/package.m4
-
+       } >package.m4-t && \
+       if diff package.m4-t $(srcdir)/package.m4 >/dev/null; then \
+         rm -f package.m4-t; \
+       else \
+         mv -f package.m4-t $(srcdir)/package.m4; \
+       fi
 
 
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