Make perl/ build procedure ActiveState friendly.

On Cygwin + ActivateState Perl, Makefile generated with
MakeMaker is not usable because of line-endings and
back-slashes.

This teaches perl/Makefile to write a handcrafted equivalent
perl.mak file with 'make NO_PERL_MAKEMAKER=NoThanks'.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

perl/.gitignore

@@ -1,4 +1,5 @@
-Makefile
+perl.mak
+perl.mak.old
 blib
 blibdirs
 pm_to_blib

perl/Makefile

@@ -0,0 +1,39 @@
+#
+# Makefile for perl support modules and routine
+#
+makfile:=perl.mak
+
+PERL_PATH_SQ = $(subst ','\'',$(PERL_PATH))
+prefix_SQ = $(subst ','\'',$(prefix))
+
+all install instlibdir: $(makfile)
+	$(MAKE) -f $(makfile) $@
+
+clean:
+	test -f $(makfile) && $(MAKE) -f $(makfile) $@ || exit 0
+	$(RM) ppport.h
+	$(RM) $(makfile)
+	$(RM) $(makfile).old
+
+ifdef NO_PERL_MAKEMAKER
+instdir_SQ = $(subst ','\'',$(prefix)/lib)
+$(makfile): ../GIT-CFLAGS Makefile
+	echo all: > $@
+	echo '	:' >> $@
+	echo install: >> $@
+	echo '	mkdir -p $(instdir_SQ)' >> $@
+	echo '	$(RM) $(instdir_SQ)/Git.pm; cp Git.pm $(instdir_SQ)' >> $@
+	echo '	$(RM) $(instdir_SQ)/Error.pm; \
+	cp private-Error.pm $(instdir_SQ)/Error.pm' >> $@
+	echo instlibdir: >> $@
+	echo '	echo $(instdir_SQ)' >> $@
+else
+$(makfile): Makefile.PL ../GIT-CFLAGS
+	'$(PERL_PATH_SQ)' $< FIRST_MAKEFILE='$@' PREFIX='$(prefix_SQ)'
+endif
+
+# this is just added comfort for calling make directly in perl dir
+# (even though GIT-CFLAGS aren't used yet. If ever)
+../GIT-CFLAGS:
+	$(MAKE) -C .. GIT-CFLAGS
+