Gitweb: add support for minifying gitweb.css

The build system added support minifying gitweb.js through a
JavaScript minifier, but most minifiers come with support for
minifying CSS files as well, so we should use it if we can.

This patch will add the same facilities to gitweb.css that
gitweb.js has for minification. That does not mean that they
will use the same minifier though, as it is not safe to assume
that all JavaScript minifiers will also minify CSS files.

This patch also adds the GITWEB_PROGRAMS variable to the Makefile
to keep a list of potential gitweb dependencies separate from
OTHER_PROGRAMS when we need to know just the gitweb dependencies.

Though the bandwidth savings will not be as dramatic as with
the JavaScript minifier, every byte saved is important.

Signed-off-by: Mark Rada <marada@uwaterloo.ca>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

4 files changed, 43 insertions, 14 deletions

diff --git a/Makefile b/Makefile
index 62a029ccc4..9bebcf1c44 100644
--- a/Makefile
+++ b/Makefile
@@ -203,6 +203,9 @@ all::
 # Define JSMIN to point to JavaScript minifier that functions as
 # a filter to have gitweb.js minified.
 #
+# Define CSSMIN to point to a CSS minifier in order to generate a minified
+# version of gitweb.css
+#
 # Define DEFAULT_PAGER to a sensible pager command (defaults to "less") if
 # you want to use something different.  The value will be interpreted by the
 # shell at runtime when it is used.
@@ -279,8 +282,9 @@ lib = lib
 # DESTDIR=
 pathsep = :
 
-# JavaScript minifier invocation that can function as filter
+# JavaScript/CSS minifier invocation that can function as filter
 JSMIN =
+CSSMIN =
 
 export prefix bindir sharedir sysconfdir
 
@@ -1560,18 +1564,23 @@ gitweb:
 	$(QUIET_SUBDIR0)gitweb $(QUIET_SUBDIR1) all
 
 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
+GITWEB_PROGRAMS += gitweb/gitweb.min.js
 endif
+ifdef CSSMIN
+GITWEB_PROGRAMS += gitweb/gitweb.min.css
+endif
+OTHER_PROGRAMS +=  gitweb/gitweb.cgi  $(GITWEB_PROGRAMS)
+gitweb/gitweb.cgi: gitweb/gitweb.perl $(GITWEB_PROGRAMS)
 	$(QUIET_SUBDIR0)gitweb $(QUIET_SUBDIR1) $(patsubst gitweb/%,%,$@)
 
 ifdef JSMIN
 gitweb/gitweb.min.js: gitweb/gitweb.js
 	$(QUIET_SUBDIR0)gitweb $(QUIET_SUBDIR1) $(patsubst gitweb/%,%,$@)
 endif # JSMIN
+ifdef CSSMIN
+gitweb/gitweb.min.css: gitweb/gitweb.css
+	$(QUIET_SUBDIR0)gitweb $(QUIET_SUBDIR1) $(patsubst gitweb/%,%,$@)
+endif # CSSMIN
 
 
 git-instaweb: git-instaweb.sh gitweb/gitweb.cgi gitweb/gitweb.css gitweb/gitweb.js
diff --git a/gitweb/INSTALL b/gitweb/INSTALL
index b76a0cffff..b75a90be7d 100644
--- a/gitweb/INSTALL
+++ b/gitweb/INSTALL
@@ -66,6 +66,11 @@ file for gitweb (in gitweb/README).
   build configuration variables. By default gitweb tries to find them
   in the same directory as gitweb.cgi script.
 
+- You can optionally generate a minified version of gitweb.css by defining
+  the CSSMIN build configuration variable. By default the non-minified
+  version of gitweb.css will be used. NOTE: if you enable this option,
+  substitute gitweb.min.css for all uses of gitweb.css in the help files.
+
 Build example
 ~~~~~~~~~~~~~
 
diff --git a/gitweb/Makefile b/gitweb/Makefile
index c9eb1ee667..fffe700760 100644
--- a/gitweb/Makefile
+++ b/gitweb/Makefile
@@ -6,13 +6,17 @@ all::
 # Define JSMIN to point to JavaScript minifier that functions as
 # a filter to have gitweb.js minified.
 #
+# Define CSSMIN to point to a CSS minifier in order to generate a minified
+# version of gitweb.css
+#
 
 prefix ?= $(HOME)
 bindir ?= $(prefix)/bin
 RM ?= rm -f
 
-# JavaScript minifier invocation that can function as filter
+# JavaScript/CSS minifier invocation that can function as filter
 JSMIN ?=
+CSSMIN ?=
 
 # default configuration for gitweb
 GITWEB_CONFIG = gitweb_config.perl
@@ -26,7 +30,11 @@ GITWEB_STRICT_EXPORT =
 GITWEB_BASE_URL =
 GITWEB_LIST =
 GITWEB_HOMETEXT = indextext.html
+ifdef CSSMIN
+GITWEB_CSS = gitweb.min.css
+else
 GITWEB_CSS = gitweb.css
+endif
 GITWEB_LOGO = git-logo.png
 GITWEB_FAVICON = git-favicon.png
 ifdef JSMIN
@@ -84,13 +92,14 @@ endif
 
 all:: gitweb.cgi
 
+FILES = gitweb.cgi
 ifdef JSMIN
-FILES=gitweb.cgi gitweb.min.js
-gitweb.cgi: gitweb.perl gitweb.min.js
-else # !JSMIN
-FILES=gitweb.cgi
-gitweb.cgi: gitweb.perl
-endif # JSMIN
+FILES += gitweb.min.js
+endif
+ifdef CSSMIN
+FILES += gitweb.min.css
+endif
+gitweb.cgi: gitweb.perl $(GITWEB_JS) $(GITWEB_CSS)
 
 gitweb.cgi:
 	$(QUIET_GEN)$(RM) $@ $@+ && \
@@ -123,6 +132,11 @@ gitweb.min.js: gitweb.js
 	$(QUIET_GEN)$(JSMIN) <$< >$@
 endif # JSMIN
 
+ifdef CSSMIN
+gitweb.min.css: gitweb.css
+	$(QUIET_GEN)$(CSSMIN) <$ >$@
+endif
+
 clean:
 	$(RM) $(FILES)
 
diff --git a/gitweb/README b/gitweb/README
index ad6a04c464..71742b335d 100644
--- a/gitweb/README
+++ b/gitweb/README
@@ -80,7 +80,8 @@ You can specify the following configuration variables when building GIT:
    Points to the location where you put gitweb.css on your web server
    (or to be more generic, the URI of gitweb stylesheet).  Relative to the
    base URI of gitweb.  Note that you can setup multiple stylesheets from
-   the gitweb config file.  [Default: gitweb.css]
+   the gitweb config file.  [Default: gitweb.css (or gitweb.min.css if the
+   CSSMIN variable is defined / CSS minifier is used)]
  * GITWEB_LOGO
    Points to the location where you put git-logo.png on your web server
    (or to be more generic URI of logo, 72x27 size, displayed in top right