Merge branch 'hotfix/4148'

Close zendframework/zendframework#4148

src/FilterChain.php

@@ -184,8 +184,8 @@ public function attachByName($name, $options = array(), $priority = self::DEFAUL
      */
     public function merge(FilterChain $filterChain)
     {
-        foreach ($filterChain->filters as $filter) {
-            $this->attach($filter);
+        foreach ($filterChain->filters->toArray(PriorityQueue::EXTR_BOTH) as $item) {
+            $this->attach($item['data'], $item['priority']);
         }
 
         return $this;

test/FilterChainTest.php

@@ -183,6 +183,38 @@ public function testCanSerializeFilterChain()
         $valueExpected = 'abc';
         $this->assertEquals($valueExpected, $unserialized->filter($value));
     }
+
+    public function testMergingTwoFilterChainsKeepFiltersPriority()
+    {
+        $value         = 'AbC';
+        $valueExpected = 'abc';
+
+        $chain = new FilterChain();
+        $chain->attach(new StripUpperCase())
+              ->attach(new LowerCase(), 1001);
+        $this->assertEquals($valueExpected, $chain->filter($value));
+
+        $chain = new FilterChain();
+        $chain->attach(new LowerCase(), 1001)
+              ->attach(new StripUpperCase());
+        $this->assertEquals($valueExpected, $chain->filter($value));
+
+        $chain = new FilterChain();
+        $chain->attach(new LowerCase(), 1001);
+        $chainToMerge = new FilterChain();
+        $chainToMerge->attach(new StripUpperCase());
+        $chain->merge($chainToMerge);
+        $this->assertEquals(2, $chain->count());
+        $this->assertEquals($valueExpected, $chain->filter($value));
+
+        $chain = new FilterChain();
+        $chain->attach(new StripUpperCase());
+        $chainToMerge = new FilterChain();
+        $chainToMerge->attach(new LowerCase(), 1001);
+        $chain->merge($chainToMerge);
+        $this->assertEquals(2, $chain->count());
+        $this->assertEquals($valueExpected, $chain->filter($value));
+    }
 }