Makefile: use git init/add/commit/archive for dist-doc

Reduce the dependency on external tools by generating the distribution
archives for HTML documentation and manpages using git commands instead
of tar. This gives the archive entries the same meta data as those in
the dist archive for binaries.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -3105,11 +3105,15 @@ artifacts-tar:: $(ALL_COMMANDS_TO_INSTALL) $(SCRIPT_LIB) $(OTHER_PROGRAMS) \
 htmldocs = git-htmldocs-$(GIT_VERSION)
 manpages = git-manpages-$(GIT_VERSION)
 .PHONY: dist-doc distclean
-dist-doc:
+dist-doc: git$X
 	$(RM) -r .doc-tmp-dir
 	mkdir .doc-tmp-dir
 	$(MAKE) -C Documentation WEBDOC_DEST=../.doc-tmp-dir install-webdoc
-	cd .doc-tmp-dir && $(TAR) cf ../$(htmldocs).tar $(TAR_DIST_EXTRA_OPTS) .
+	./git -C .doc-tmp-dir init
+	./git -C .doc-tmp-dir add .
+	./git -C .doc-tmp-dir commit -m htmldocs
+	./git -C .doc-tmp-dir archive --format=tar --prefix=./ HEAD^{tree} \
+		> $(htmldocs).tar
 	gzip -n -9 -f $(htmldocs).tar
 	:
 	$(RM) -r .doc-tmp-dir
@@ -3119,7 +3123,11 @@ dist-doc:
 		man5dir=../.doc-tmp-dir/man5 \
 		man7dir=../.doc-tmp-dir/man7 \
 		install
-	cd .doc-tmp-dir && $(TAR) cf ../$(manpages).tar $(TAR_DIST_EXTRA_OPTS) .
+	./git -C .doc-tmp-dir init
+	./git -C .doc-tmp-dir add .
+	./git -C .doc-tmp-dir commit -m manpages
+	./git -C .doc-tmp-dir archive --format=tar --prefix=./ HEAD^{tree} \
+		> $(manpages).tar
 	gzip -n -9 -f $(manpages).tar
 	$(RM) -r .doc-tmp-dir