FIX: case-insensitive category lookup when creating topics

app/models/category.rb

@@ -32,6 +32,7 @@ class Category < ActiveRecord::Base
   before_validation :ensure_slug
   before_save :apply_permissions
   before_save :downcase_email
+  before_save :downcase_name
   after_create :create_category_definition
   after_create :publish_categories_list
   after_destroy :publish_categories_list
@@ -254,6 +255,10 @@ SQL
     self.email_in = email_in.downcase if self.email_in
   end
 
+  def downcase_name
+    self.name_lower = name.downcase if self.name
+  end
+
   def secure_group_ids
     if self.read_restricted?
       groups.pluck("groups.id")

db/migrate/20140815215618_add_name_lower_to_categories.rb

@@ -0,0 +1,13 @@
+class AddNameLowerToCategories < ActiveRecord::Migration
+
+  def up
+    add_column :categories, :name_lower, :string, limit: 50
+    execute "update categories set name_lower = lower(name)"
+    change_column :categories, :name_lower, :string, limit: 50, null:false
+  end
+
+  def down
+    remove_column :categories, :name_lower
+  end
+
+end

lib/topic_creator.rb

@@ -73,7 +73,7 @@ class TopicCreator
     if (@opts[:category].is_a? Integer) || (@opts[:category] =~ /^\d+$/)
       Category.find_by(id: @opts[:category])
     else
-      Category.find_by(name: @opts[:category])
+      Category.find_by(name_lower: @opts[:category].try(:downcase))
     end
   end
 

spec/components/topic_creator_spec.rb

@@ -40,6 +40,13 @@ describe TopicCreator do
           topic.should be_valid
           topic.auto_close_at.should be_nil
         end
+
+        it "category name is case insensitive" do
+          category = Fabricate(:category, name: "Neil's Blog")
+          topic = TopicCreator.create(user, Guardian.new(user), valid_attrs.merge(category: "neil's blog"))
+          topic.should be_valid
+          topic.category.should == category
+        end
       end
     end
   end

spec/models/category_spec.rb

@@ -148,6 +148,10 @@ describe Category do
     Fabricate(:category, name: "  blanks ").name.should == "blanks"
   end
 
+  it "sets name_lower" do
+    Fabricate(:category, name: "Not MySQL").name_lower.should == "not mysql"
+  end
+
   it "has custom fields" do
     category = Fabricate(:category, name: " music")
     category.custom_fields["a"].should == nil