Merge branch '2.3' into 2.7

* 2.3:
  [DomCrawler] Clarify the value returned by getPhpFiles()
  [DependencyInjection] Fix #16461 Let Container::set() replace existing aliases
  Added more exceptions to singularify method

Author: nicolas-grekas

Container.php

@@ -193,6 +193,10 @@ public function set($id, $service, $scope = self::SCOPE_CONTAINER)
             $this->scopedServices[$scope][$id] = $service;
         }
 
+        if (isset($this->aliases[$id])) {
+            unset($this->aliases[$id]);
+        }
+
         $this->services[$id] = $service;
 
         if (method_exists($this, $method = 'synchronize'.strtr($id, $this->underscoreMap).'Service')) {

Tests/ContainerBuilderTest.php

@@ -218,6 +218,16 @@ public function testAddAliases()
         $this->assertTrue(isset($aliases['foobar']));
     }
 
+    public function testSetReplacesAlias()
+    {
+        $builder = new ContainerBuilder();
+        $builder->setAlias('alias', 'aliased');
+        $builder->set('aliased', new \stdClass());
+
+        $builder->set('alias', $foo = new \stdClass());
+        $this->assertSame($foo, $builder->get('alias'), '->set() replaces an existing alias');
+    }
+
     public function testAddGetCompilerPass()
     {
         $builder = new ContainerBuilder();

Tests/ContainerTest.php

@@ -184,6 +184,14 @@ public function testSetAlsoCallsSynchronizeService()
         $this->assertTrue($c->synchronized, '->set() calls synchronize*Service() if it is defined for the service');
     }
 
+    public function testSetReplacesAlias()
+    {
+        $c = new ProjectServiceContainer();
+
+        $c->set('alias', $foo = new \stdClass());
+        $this->assertSame($foo, $c->get('alias'), '->set() replaces an existing alias');
+    }
+
     public function testGet()
     {
         $sc = new ProjectServiceContainer();