1 files changed, 76 insertions, 9 deletions

diff --git a/template/en/default/global/header.html.tmpl b/template/en/default/global/header.html.tmpl
index e4a5f4954..026698426 100644
--- a/template/en/default/global/header.html.tmpl
+++ b/template/en/default/global/header.html.tmpl
@@ -46,6 +46,7 @@
   h2 = ""
   h3 = ""
   onload = ""
+  style_urls = []
 %]
 
 [%# We should be able to set the default value of the h1 variable
@@ -67,6 +68,8 @@
 
     [% PROCESS "global/site-navigation.html.tmpl" %]
 
+    [% PROCESS 'global/setting-descs.none.tmpl' %]
+
     [% IF javascript %]
       <script type="text/javascript">
         [% javascript %]
@@ -81,22 +84,86 @@
 
     [%+ INCLUDE "global/help-header.html.tmpl" %]
 
-    <link href="skins/standard/global.css" rel="stylesheet" type="text/css">
-    <link href="skins/custom/global.css" rel="stylesheet" type="text/css">
+    [%# Set up the skin CSS cascade:
+      #  1. Standard Bugzilla stylesheet set (persistent)
+      #  2. Standard Bugzilla stylesheet set (selectable)
+      #  3. All third-party "skin" stylesheet sets (selectable)
+      #  4. Page-specific styles
+      #  5. Custom Bugzilla stylesheet set (persistent)
+      # "Selectable" skin file sets may be either preferred or alternate.
+      # Exactly one is preferred, determined by the "skin" user preference.
+      #%]
+    [% IF user.settings.skin.value != 'standard' %]
+      [% user_skin = user.settings.skin.value %]
+    [% END %]
+    [% style_urls.unshift('skins/standard/global.css') %]
+
+    [%# CSS cascade, part 1: Standard Bugzilla stylesheet set (persistent).
+      # Always present.
+      #%]
+    [% FOREACH style_url = style_urls %]
+      <link href="[% style_url FILTER html %]"
+            rel="stylesheet"
+            type="text/css">
+    [% END %]
+
+    [%# CSS cascade, part 2: Standard Bugzilla stylesheet set (selectable)
+      # Present if skin selection is enabled.
+      #%]
+    [% IF user.settings.skin.is_enabled %]
+      [% FOREACH style_url = style_urls %]
+        <link href="[% style_url FILTER html %]"
+              rel="[% 'alternate ' IF user_skin %]stylesheet"
+              title="[% setting_descs.standard FILTER html %]"
+              type="text/css">
+      [% END %]
+    [% END %]
 
+    [%# CSS cascade, part 3: Third-party stylesheet set (selectable).
+      # All third-party skins are present if skin selection is enabled.
+      # The admin-selected skin is always present.
+      #%]
+    [% FOREACH contrib_skin = user.settings.skin.legal_values %]
+      [% NEXT IF contrib_skin == 'standard' %]
+      [% NEXT UNLESS contrib_skin == user_skin
+                  OR user.settings.skin.is_enabled %]
+      [% contrib_skin = contrib_skin FILTER url_quote %]
+      [% IF contrib_skin.match('\.css$') %]
+        [%# 1st skin variant: single-file stylesheet %]
+        <link href="[% "skins/contrib/$contrib_skin" %]"
+              rel="[% 'alternate ' UNLESS contrib_skin == user_skin %]stylesheet"
+              title="[% contrib_skin FILTER html %]"
+              type="text/css">
+      [% ELSE %]
+        [%# 2nd skin variant: stylesheet set %]
+        [% FOREACH style_url = style_urls %]
+          [% IF style_url.match('^skins/standard/') %]
+            <link href="[% style_url.replace('^skins/standard/',
+                                             "skins/contrib/$contrib_skin/") %]"
+                  rel="[% 'alternate ' UNLESS contrib_skin == user_skin %]stylesheet"
+                  title="[% contrib_skin FILTER html %]"
+                  type="text/css">
+          [% END %]
+        [% END %]
+      [% END %]
+    [% END %]
+
+    [%# CSS cascade, part 4: page-specific styles.
+      #%]
     [% IF style %]
       <style type="text/css">
         [% style %]
       </style>
     [% END %]
 
-    [% IF style_urls %]
-      [% FOREACH style_url = style_urls %]
-        <link href="[% style_url FILTER html %]" rel="stylesheet" type="text/css">
-        [% IF style_url.match('^skins/standard/') %]
-          <link href="[% style_url.replace('^skins/standard/', 'skins/custom/')
-                         FILTER html %]" rel="stylesheet" type="text/css">
-        [% END %]
+    [%# CSS cascade, part 5: Custom Bugzilla stylesheet set (persistent).
+      # Always present. Site administrators may override all other style
+      # definitions, including skins, using custom stylesheets.
+      #%]
+    [% FOREACH style_url = style_urls %]
+      [% IF style_url.match('^skins/standard/') %]
+        <link href="[% style_url.replace('^skins/standard/', "skins/custom/")
+                       FILTER html %]" rel="stylesheet" type="text/css">
       [% END %]
     [% END %]