Don't call run_on_change guard method when there is no matched files.

lib/guard.rb

@@ -30,6 +30,7 @@ module Guard
         Interactor.init_signal_traps
         
         listener.on_change do |files|
+          if Watcher.match_files?(guards, files)
             run do
               guards.each do |guard|
                 paths = Watcher.match_files(guard, files)
@@ -37,6 +38,7 @@ module Guard
               end
             end
           end
+        end
         
         UI.info "Guard is now watching at '#{Dir.pwd}'"
         guards.each { |g| supervised_task(g, :start) }

lib/guard/watcher.rb

@@ -30,5 +30,9 @@ module Guard
       end
     end
     
+    def self.match_files?(guards, files)
+      guards.any? { |guard| !match_files(guard, files).empty? }
+    end
+    
   end
 end