Make/CSS: Put icons.css file hash in the URL

Advantage is that it's both more robust and avoids unecessary reloads
when the file hasn't changed. The -strip argument to convert is needed
in order to generate icons.png in a deterministic way; without that it
includes a creation timestamp in the file metadata.

3 files changed, 3 insertions, 3 deletions

diff --git a/Makefile b/Makefile
index ad99c196..816f8d20 100644
--- a/Makefile
+++ b/Makefile
@@ -93,7 +93,7 @@ static/g/icons.opt.png: static/g/icons.png
 	zopflipng -m --lossy_transparent $< $@
 
 static/g/%.css: css/skins/%.sass css/v2.css data/icons/icons.css | static/g
-	( echo '$$version: "$(shell git show-ref --head --abbrev -s HEAD)";'; echo '@import "css/skins/$*"' ) | sassc --stdin -I. --style compressed >$@
+	( echo '$$icons-version: "$(shell sha1sum static/g/icons.png | head -c8)";'; echo '@import "css/skins/$*"' ) | sassc --stdin -I. --style compressed >$@
 
 
 
diff --git a/css/v2.css b/css/v2.css
index b3bc51f7..e29e9142 100644
--- a/css/v2.css
+++ b/css/v2.css
@@ -1228,7 +1228,7 @@ div.imagebrowse { padding: 0; display: flex; flex-wrap: wrap }
 /****** Icons *******/
 
 .icons {
-  background: url(/g/icons.png??#{$version}) no-repeat;
+  background: url(/g/icons.png?#{$icons-version}) no-repeat;
   width: 16px;
   height: 14px;
   margin: 0 2px 0 0;
diff --git a/util/spritegen.pl b/util/spritegen.pl
index c2644883..26cd4da8 100755
--- a/util/spritegen.pl
+++ b/util/spritegen.pl
@@ -98,7 +98,7 @@ sub img {
     my($w, $h) = @_;
     my @cmd = (config->{convert_path}, -size => "${w}x$h", 'canvas:rgba(0,0,0,0)',
         map(+($_->{p}, -geometry => "+$_->{x}+$_->{y}", '-composite'), @img),
-        "png32:$ticons"
+        '-strip', "png32:$ticons"
     );
     system(@cmd);
 }