Merge pull request slimphp#785 from qyanu/release-2.4.3

branch release-2.4.1 dropped without merging fixes?

Slim/Slim.php

@@ -1237,6 +1237,10 @@ public function clearHooks($name = null)
      */
     public function add(\Slim\Middleware $newMiddleware)
     {
+        if(in_array($newMiddleware, $this->middleware)) {
+            $middleware_class = get_class($newMiddleware);
+            throw new \RuntimeException("Circular Middleware setup detected. Tried to queue the same Middleware instance ({$middleware_class}) twice.");
+        }
         $newMiddleware->setApplication($this);
         $newMiddleware->setNextMiddleware($this->middleware[0]);
         array_unshift($this->middleware, $newMiddleware);
@@ -1295,6 +1299,8 @@ public function run()
             echo $body;
         }
 
+        $this->applyHook('slim.after');
+
         restore_error_handler();
     }
 
@@ -1333,7 +1339,6 @@ public function call()
             $this->stop();
         } catch (\Slim\Exception\Stop $e) {
             $this->response()->write(ob_get_clean());
-            $this->applyHook('slim.after');
         } catch (\Exception $e) {
             if ($this->config('debug')) {
                 throw $e;

tests/SlimTest.php

@@ -1228,6 +1228,25 @@ public function testAddMiddleware()
         $this->assertEquals('Hello', $s->response()->header('X-Slim-Test'));
     }
 
+    /**
+     * Test exception when adding circular middleware queues
+     *
+     * This asserts that the same middleware can NOT be queued twice (usually by accident).
+     * Circular middleware stack causes a troublesome to debug PHP Fatal error:
+     * 
+     * > Fatal error: Maximum function nesting level of '100' reached. aborting!
+     */
+    public function testFailureWhenAddingCircularMiddleware()
+    {
+        $this->setExpectedException('\RuntimeException');
+        $middleware = new CustomMiddleware;
+        $s = new \Slim\Slim;
+        $s->add($middleware);
+        $s->add(new CustomMiddleware);
+        $s->add($middleware);
+        $s->run();
+    }
+
     /************************************************
      * FLASH MESSAGING
      ************************************************/