patch-doc__Makefile.in

--- doc/Makefile.in.orig
+++ doc/Makefile.in
@@ -308,15 +308,15 @@
 	dir="$(dir)"; \
 	for lang in $$dir; do \
 		if test -r $(MKINSTALLDIRS); then \
-			$(MKINSTALLDIRS) $(pkgdatadir)/help/$$lang; \
+			$(MKINSTALLDIRS) $(DESTDIR)$(pkgdatadir)/help/$$lang; \
 		else \
-			$(top_srcdir)/mkinstalldirs $(pkgdatadir)/help/$$lang; \
+			$(top_srcdir)/mkinstalldirs $(DESTDIR)$(pkgdatadir)/help/$$lang; \
 		fi; \
 	done; \
 	data="$(data)"; \
 	for lang in $$dir; do \
 		for file in $$data; do \
-			$(INSTALL_DATA) $(srcdir)/$$lang/$$file $(pkgdatadir)/help/$$lang/$$file; \
+			$(INSTALL_DATA) $(srcdir)/$$lang/$$file $(DESTDIR)$(pkgdatadir)/help/$$lang/$$file; \
 		done; \
 	done;