break fixup unless it does any good

src/gen/Makefile.am

@@ -36,7 +36,14 @@ fixup.remove fixup.reorder fixup.out:
 	- rm dcs_classifier.c dcs_classifier.h dcs_type.c
 	$(MAKE) $(AM_MAKEFLAGS) dcs_classifier.c dcs_classifier.h dcs_type.c
 	( cd .. ; $(MAKE) $(AM_MAKEFLAGS) dcs_test )
+	prev=99999; \
 	while ! ../dcs_test fixup.remove fixup.reorder >>fixup.out ; do \
+		cur=$$? ; \
+		if test $$cur -ge $$prev ; then \
+			echo number of errors is not decreasing - failing fixup ; \
+			exit $$cur ; \
+		fi ; \
+		prev=$$cur ; \
 		( rm dcs_classifier.c dcs_classifier.h ; \
 		  if ! $(MAKE) $(AM_MAKEFLAGS) dcs_classifier.c dcs_classifier.h dcs_type.c ; then break ; fi ; \
 		  cd .. ; $(MAKE) $(AM_MAKEFLAGS) dcs_test ) \