fix several bugs.

Makefile.in

@@ -246,6 +246,7 @@ maintainer-clean-tags:
 distdir = $(PACKAGE)-$(VERSION)
 top_distdir = $(distdir)
 
+
 # This target untars the dist file and tries a VPATH configuration.  Then
 # it guarantees that the distribution is self-contained by making another
 # tarfile.
@@ -262,7 +263,11 @@ distcheck: dist
 	  && $(MAKE) $(AM_MAKEFLAGS) check \
 	  && $(MAKE) $(AM_MAKEFLAGS) install \
 	  && $(MAKE) $(AM_MAKEFLAGS) installcheck \
-	  && $(MAKE) $(AM_MAKEFLAGS) dist
+	  && $(MAKE) $(AM_MAKEFLAGS) uninstall \
+	  && test `find $$dc_install_base -type f -print | wc -l` -le 1 \
+	  && $(MAKE) $(AM_MAKEFLAGS) dist \
+	  && $(MAKE) $(AM_MAKEFLAGS) distclean \
+	  && test `find . -type f -print | wc -l` -eq 0
 	-rm -rf $(distdir)
 	@banner="$(distdir).tar.gz is ready for distribution"; \
 	dashes=`echo "$$banner" | sed s/./=/g`; \
@@ -349,6 +354,7 @@ distclean-generic:
 	-rm -f config.cache config.log stamp-h stamp-h[0-9]*
 
 maintainer-clean-generic:
+	-rm -f Makefile.in
 mostlyclean-am:  mostlyclean-hdr mostlyclean-tags mostlyclean-generic
 
 mostlyclean: mostlyclean-recursive