avoid duplicate requests to the cache proxy. fix #125

Author: dbu

src/ProxyClient/AbstractProxyClient.php

@@ -130,7 +130,10 @@ public function flush()
      */
     protected function queueRequest($method, $url, array $headers = array())
     {
-        $this->queue[] = $this->createRequest($method, $url, $headers);
+        $signature = md5($method . "\n" . $url . "\n" . implode("\n", $headers));
+        if (!isset($this->queue[$signature])) {
+            $this->queue[$signature] = $this->createRequest($method, $url, $headers);
+        }
     }
 
     /**

tests/Unit/ProxyClient/VarnishTest.php

@@ -347,6 +347,8 @@ function ($requests) use ($self) {
             $varnish
                 ->purge('/c')
                 ->purge('/b')
+                ->purge('/b')
+                ->purge('/b')
                 ->flush()
         );
     }