Fix distribution of dx-stamp.m4.

The automatic distribution of dx-stamp.m4 depends on m4_include
appearing in the m4 traces.  Normally aclocal does that but it
seems to not be entirely reliable.  The reason we do not simply
use m4_include is because this produces warnings about multiple
inclusion.

Fortunately, this is pretty easy to work around.  Just use m4_pushdef
to redefine m4_include to what we need, so the traces show the file
needs to be distributed.

diff --git a/m4/base.m4 b/m4/base.m4
index 5be583c9f75b44b86947ff56d0d876f286f0e275..aebf6cde1438800bb825edaa970088f56bf3ae43 100644 (file)
--- a/m4/base.m4
+++ b/m4/base.m4
@@ -31,7 +31,9 @@ m4_define([_DX_BASEDIR], m4_if([$1], [],
 dnl Include the stamp file, which will cause a failure at autoconf time
 dnl if it does not exist in the checkout.  We circumvent m4_include to
 dnl avoid warnings about multiple inclusions.
-m4_builtin([include], m4_defn([_DX_BASEDIR])[/m4/dx-stamp.m4])
+m4_pushdef([m4_include], [m4_builtin([include], $][@)])
+m4_include(m4_defn([_DX_BASEDIR])[/m4/dx-stamp.m4])
+m4_popdef([m4_include])
 _DX_STAMP_DUMMY
 
 dnl Autoconf scripts should use the DX_BASEDIR m4 macro instead of the