bug #28444 [VarDumper] fix dumping signature of callables (nicolas-grekas)

This PR was merged into the 4.2-dev branch.

Discussion
----------

[VarDumper] fix dumping signature of callables

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Adds missing visual hint when returning by reference + makes exclude-verbose mode display only the signature.

E.g. using psysh, before:
![image](https://user-images.githubusercontent.com/243674/45360788-ebe0bf80-b5d0-11e8-8e43-62f954e926af.png)

after:
![image](https://user-images.githubusercontent.com/243674/45360760-d9668600-b5d0-11e8-820a-98cc174ba2ca.png)

(`dump -a` shows the details as usual.)

Commits
-------

16f2bd58d9 [VarDumper] fix dumping signature of callables

src/Symfony/Component/VarDumper/Caster/ClassStub.php

@@ -70,9 +70,6 @@ class ClassStub extends ConstStub
                 } else {
                     $this->value .= $s;
                 }
-                if (isset($this->attr['ellipsis'])) {
-                    $this->attr['ellipsis'] += \strlen($this->value) - \strlen($identifier);
-                }
             }
         } catch (\ReflectionException $e) {
             return;

src/Symfony/Component/VarDumper/Caster/ReflectionCaster.php

@@ -33,13 +33,22 @@ class ReflectionCaster
 
     public static function castClosure(\Closure $c, array $a, Stub $stub, $isNested, $filter = 0)
     {
-        $prefix = Caster::PREFIX_VIRTUAL;
         $c = new \ReflectionFunction($c);
 
         $a = static::castFunctionAbstract($c, $a, $stub, $isNested, $filter);
 
         $stub->class .= self::getSignature($a);
 
+        $prefix = Caster::PREFIX_DYNAMIC;
+        unset($a['name'], $a[$prefix.'this'], $a[$prefix.'parameter'], $a[Caster::PREFIX_VIRTUAL.'extra']);
+        $prefix = Caster::PREFIX_VIRTUAL;
+
+        if ($filter & Caster::EXCLUDE_VERBOSE) {
+            $stub->cut += ($c->getFileName() ? 2 : 0) + \count($a);
+
+            return array();
+        }
+
         if (isset($a[$prefix.'parameters'])) {
             foreach ($a[$prefix.'parameters']->value as &$v) {
                 $param = $v;
@@ -53,14 +62,11 @@ class ReflectionCaster
             }
         }
 
-        if (!($filter & Caster::EXCLUDE_VERBOSE) && $f = $c->getFileName()) {
+        if ($f = $c->getFileName()) {
             $a[$prefix.'file'] = new LinkStub($f, $c->getStartLine());
             $a[$prefix.'line'] = $c->getStartLine().' to '.$c->getEndLine();
         }
 
-        $prefix = Caster::PREFIX_DYNAMIC;
-        unset($a['name'], $a[$prefix.'this'], $a[$prefix.'parameter'], $a[Caster::PREFIX_VIRTUAL.'extra']);
-
         return $a;
     }
 
@@ -333,7 +339,7 @@ class ReflectionCaster
                 }
             }
         }
-        $signature = '('.substr($signature, 2).')';
+        $signature = (empty($a[$prefix.'returnsReference']) ? '' : '&').'('.substr($signature, 2).')';
 
         if (isset($a[$prefix.'returnType'])) {
             $signature .= ': '.substr(strrchr('\\'.$a[$prefix.'returnType'], '\\'), 1);

src/Symfony/Component/VarDumper/Tests/Caster/ReflectionCasterTest.php

@@ -87,16 +87,9 @@ EOTXT
 
     public function testClosureCasterExcludingVerbosity()
     {
-        $var = function () {};
+        $var = function &($a = 5) {};
 
-        $expectedDump = <<<EOTXT
+        $this->assertDumpEquals('Closure&($a = 5) { …6}', $var, Caster::EXCLUDE_VERBOSE);
-Closure() {
-  class: "Symfony\Component\VarDumper\Tests\Caster\ReflectionCasterTest"
-  this: Symfony\Component\VarDumper\Tests\Caster\ReflectionCasterTest { …}
-}
-EOTXT;
-
-        $this->assertDumpEquals($expectedDump, $var, Caster::EXCLUDE_VERBOSE);
     }
 
     public function testReflectionParameter()