gitweb: Minify gitweb.js if JSMIN is defined

It requires that $JSMIN command can function as a filter.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -198,6 +198,9 @@ all::
 # memory allocators with the nedmalloc allocator written by Niall Douglas.
 #
 # Define NO_REGEX if you have no or inferior regex support in your C library.
+#
+# Define JSMIN to point to JavaScript minifier that functions as
+# a filter to have gitweb.js minified.
 
 GIT-VERSION-FILE: .FORCE-GIT-VERSION-FILE
 	@$(SHELL_PATH) ./GIT-VERSION-GEN
@@ -250,6 +253,9 @@ lib = lib
 # DESTDIR=
 pathsep = :
 
+# JavaScript minifier invocation that can function as filter
+JSMIN =
+
 # default configuration for gitweb
 GITWEB_CONFIG = gitweb_config.perl
 GITWEB_CONFIG_SYSTEM = /etc/gitweb.conf
@@ -265,7 +271,11 @@ GITWEB_HOMETEXT = indextext.html
 GITWEB_CSS = gitweb.css
 GITWEB_LOGO = git-logo.png
 GITWEB_FAVICON = git-favicon.png
+ifdef JSMIN
+GITWEB_JS = gitweb.min.js
+else
 GITWEB_JS = gitweb.js
+endif
 GITWEB_SITE_HEADER =
 GITWEB_SITE_FOOTER =
 
@@ -1388,8 +1398,13 @@ $(patsubst %.perl,%,$(SCRIPT_PERL)): % : %.perl
 	chmod +x $@+ && \
 	mv $@+ $@
 
+ifdef JSMIN
+OTHER_PROGRAMS += gitweb/gitweb.cgi   gitweb/gitweb.min.js
+gitweb/gitweb.cgi: gitweb/gitweb.perl gitweb/gitweb.min.js
+else
 OTHER_PROGRAMS += gitweb/gitweb.cgi
 gitweb/gitweb.cgi: gitweb/gitweb.perl
+endif
 	$(QUIET_GEN)$(RM) $@ $@+ && \
 	sed -e '1s|#!.*perl|#!$(PERL_PATH_SQ)|' \
 	    -e 's|++GIT_VERSION++|$(GIT_VERSION)|g' \
@@ -1440,6 +1455,11 @@ $(patsubst %.perl,%,$(SCRIPT_PERL)) git-instaweb: % : unimplemented.sh
 	mv $@+ $@
 endif # NO_PERL
 
+ifdef JSMIN
+gitweb/gitweb.min.js: gitweb/gitweb.js
+	$(QUIET_GEN)$(JSMIN) <$< >$@
+endif # JSMIN
+
 configure: configure.ac
 	$(QUIET_GEN)$(RM) $@ $<+ && \
 	sed -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \