[Process] Fix parsing args on Windows

src/Symfony/Component/Process/Process.php

@@ -1633,14 +1633,17 @@ class Process implements \IteratorAggregate
         $varCount = 0;
         $varCache = array();
         $cmd = preg_replace_callback(
-            '/"(
+            '/"(?:(
                 [^"%!^]*+
                 (?:
                     (?: !LF! | "(?:\^[%!^])?+" )
                     [^"%!^]*+
                 )++
-            )"/x',
+            ) | [^"]*+ )"/x',
             function ($m) use (&$envBackup, &$env, &$varCache, &$varCount, $uid) {
+                if (!isset($m[1])) {
+                    return $m[0];
+                }
                 if (isset($varCache[$m[0]])) {
                     return $varCache[$m[0]];
                 }

src/Symfony/Component/Process/Tests/ProcessTest.php

@@ -1484,6 +1484,24 @@ class ProcessTest extends TestCase
         $this->assertSame($arg, $p->getOutput());
     }
 
+    public function testRawCommandLine()
+    {
+        $p = new Process(sprintf('"%s" -r %s "a" "" "b"', self::$phpBin, escapeshellarg('print_r($argv);')));
+        $p->run();
+
+        $expected = <<<EOTXT
+Array
+(
+    [0] => -
+    [1] => a
+    [2] => 
+    [3] => b
+)
+
+EOTXT;
+        $this->assertSame($expected, $p->getOutput());
+    }
+
     public function provideEscapeArgument()
     {
         yield array('a"b%c%');