FIX: sub-categories with the same name had the same background image

app/assets/javascripts/discourse/mixins/add-category-class.js.es6

@@ -1,8 +1,8 @@
-// Mix this in to a view that has a `categorySlug` property to automatically
+// Mix this in to a view that has a `categoryFullSlug` property to automatically
 // add it to the body as the view is entered / left / model is changed.
 // This is used for keeping the `body` style in sync for the background image.
 export default {
-  _enterView: function() { this.get('categorySlug'); }.on('init'),
+  _enterView: function() { this.get('categoryFullSlug'); }.on('init'),
 
   _removeClasses: function() {
     $('body').removeClass(function(idx, css) {
@@ -11,13 +11,13 @@ export default {
   },
 
   _categoryChanged: function() {
-    var categorySlug = this.get('categorySlug');
+    var categoryFullSlug = this.get('categoryFullSlug');
     this._removeClasses();
 
-    if (categorySlug) {
-      $('body').addClass('category-' + categorySlug);
+    if (categoryFullSlug) {
+      $('body').addClass('category-' + categoryFullSlug);
     }
-  }.observes('categorySlug'),
+  }.observes('categoryFullSlug'),
 
   _leaveView: function() { this._removeClasses(); }.on('willDestroyElement')
 };

app/assets/javascripts/discourse/models/category.js

@@ -29,6 +29,10 @@ Discourse.Category = Discourse.Model.extend({
     return Discourse.getURL("/c/") + Discourse.Category.slugFor(this);
   }.property('name'),
 
+  fullSlug: function() {
+    return this.get("url").slice(3).replace("/", "-");
+  }.property("url"),
+
   nameLower: function() {
     return this.get('name').toLowerCase();
   }.property('name'),

app/assets/javascripts/discourse/models/site.js

@@ -85,15 +85,13 @@ Discourse.Site.reopenClass(Discourse.Singleton, {
     if (result.categories) {
       result.categoriesById = {};
       result.categories = _.map(result.categories, function(c) {
-        result.categoriesById[c.id] = Discourse.Category.create(c);
-        return result.categoriesById[c.id];
+        return result.categoriesById[c.id] = Discourse.Category.create(c);
       });
 
       // Associate the categories with their parents
       result.categories.forEach(function (c) {
         if (c.get('parent_category_id')) {
-          c.set('parentCategory',
-            result.categoriesById[c.get('parent_category_id')]);
+          c.set('parentCategory', result.categoriesById[c.get('parent_category_id')]);
         }
       });
     }

app/assets/javascripts/discourse/models/topic.js

@@ -48,8 +48,8 @@ Discourse.Topic = Discourse.Model.extend({
   }.property('category_id', 'categoryName'),
 
   categoryClass: function() {
-    return 'category-' + Discourse.Category.slugFor(this.get('category'));
-  }.property('category'),
+    return 'category-' + this.get('category.fullSlug');
+  }.property('category.fullSlug'),
 
   shareUrl: function(){
     var user = Discourse.User.current();

app/assets/javascripts/discourse/views/navigation-category.js.es6

@@ -1,5 +1,5 @@
 import AddCategoryClass from 'discourse/mixins/add-category-class';
 
 export default Em.View.extend(AddCategoryClass, {
-  categorySlug: Em.computed.alias('controller.category.slug')
+  categoryFullSlug: Em.computed.alias('controller.category.fullSlug')
 });

app/assets/javascripts/discourse/views/topic-list-item.js.es6

@@ -27,12 +27,11 @@ export default Discourse.View.extend(StringBuffer, {
   }.property('controller.selectedRow'),
 
   unboundClassNames: function(){
-    var classes = [];
-    var topic = this.get('topic');
-
+    let classes = [];
+    const topic = this.get('topic');
 
     if (topic.get('category')) {
-      classes.push("category-" + topic.get('category.slug'));
+      classes.push("category-" + topic.get('category.fullSlug'));
     }
 
     if(topic.get('hasExcerpt')){

app/models/category.rb

@@ -341,9 +341,9 @@ SQL
     self.where(id: parent_slug.to_i).pluck(:id).first
   end
 
-  def self.query_category(slug, parent_category_id)
-    self.where(slug: slug, parent_category_id: parent_category_id).includes(:featured_users).first ||
-    self.where(id: slug.to_i, parent_category_id: parent_category_id).includes(:featured_users).first
+  def self.query_category(slug_or_id, parent_category_id)
+    self.where(slug: slug_or_id, parent_category_id: parent_category_id).includes(:featured_users).first ||
+    self.where(id: slug_or_id.to_i, parent_category_id: parent_category_id).includes(:featured_users).first
   end
 
   def self.find_by_email(email)
@@ -366,6 +366,10 @@ SQL
     @@url_cache.clear
   end
 
+  def full_slug
+    url[3..-1].gsub("/", "-")
+  end
+
   def url
     url = @@url_cache[self.id]
     unless url

lib/sass/discourse_sass_importer.rb

@@ -50,7 +50,7 @@ class DiscourseSassImporter < Sass::Importers::Filesystem
       contents = ""
       Category.where('background_url IS NOT NULL').each do |c|
         if c.background_url.present?
-          contents << "body.category-#{c.slug} { background-image: url(#{c.background_url}) }\n"
+          contents << "body.category-#{c.full_slug} { background-image: url(#{c.background_url}) }\n"
         end
       end
       return Sass::Engine.new(contents, options.merge(