[#373] Refactoring auto_completes#issues action

hoping to make it more intention revealing

app/controllers/auto_completes_controller.rb

@@ -4,18 +4,18 @@ class AutoCompletesController < ApplicationController
   def issues
     @issues = []
     q = params[:q].to_s
-    query = (params[:scope] == "all" && Setting.cross_project_issue_relations?) ? Issue : @project.issues
-    if q.match(/^\d+$/)
-      @issues << query.visible.find_by_id(q.to_i)
-    end
-    unless q.blank?
-      @issues += query.visible.find(:all,
+
+    if q.present?
+      query = (params[:scope] == "all" && Setting.cross_project_issue_relations?) ? Issue : @project.issues
+
+      @issues |= query.visible.find_all_by_id(q.to_i) if q =~ /^\d+$/
+
+      @issues |= query.visible.find(:all,
                                     :limit => 10,
                                     :order => "#{Issue.table_name}.id ASC",
                                     :conditions => ["LOWER(#{Issue.table_name}.subject) LIKE :q OR CAST(#{Issue.table_name}.id AS CHAR(13)) LIKE :q", {:q => "%#{q.downcase}%" }])
     end
-    @issues.compact!
-    @issues.uniq!
+
     render :layout => false
   end