Add EmptyConstraint

src/Composer/Package/LinkConstraint/EmptyConstraint.php

@@ -0,0 +1,47 @@
+<?php
+
+/*
+ * This file is part of Composer.
+ *
+ * (c) Nils Adermann <naderman@naderman.de>
+ *     Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Composer\Package\LinkConstraint;
+
+/**
+ * Defines an absence of constraints
+ *
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+class EmptyConstraint implements LinkConstraintInterface
+{
+    protected $prettyString;
+
+    public function matches(LinkConstraintInterface $provider)
+    {
+        return true;
+    }
+
+    public function setPrettyString($prettyString)
+    {
+        $this->prettyString = $prettyString;
+    }
+
+    public function getPrettyString()
+    {
+        if ($this->prettyString) {
+            return $this->prettyString;
+        }
+
+        return $this->__toString();
+    }
+
+    public function __toString()
+    {
+        return '[]';
+    }
+}

src/Composer/Package/Version/VersionParser.php

@@ -15,6 +15,7 @@ namespace Composer\Package\Version;
 use Composer\Package\BasePackage;
 use Composer\Package\PackageInterface;
 use Composer\Package\Link;
+use Composer\Package\LinkConstraint\EmptyConstraint;
 use Composer\Package\LinkConstraint\MultiConstraint;
 use Composer\Package\LinkConstraint\VersionConstraint;
 
@@ -253,7 +254,7 @@ class VersionParser
         }
 
         if (preg_match('{^[x*](\.[x*])*$}i', $constraint)) {
-            return array();
+            return array(new EmptyConstraint);
         }
 
         if (preg_match('{^~(\d+)(?:\.(\d+))?(?:\.(\d+))?(?:\.(\d+))?'.self::$modifierRegex.'?$}i', $constraint, $matches)) {

tests/Composer/Test/Package/Version/VersionParserTest.php

@@ -15,6 +15,7 @@ namespace Composer\Test\Package\Version;
 use Composer\Package\Version\VersionParser;
 use Composer\Package\LinkConstraint\MultiConstraint;
 use Composer\Package\LinkConstraint\VersionConstraint;
+use Composer\Package\LinkConstraint\EmptyConstraint;
 use Composer\Package\PackageInterface;
 
 class VersionParserTest extends \PHPUnit_Framework_TestCase
@@ -192,10 +193,10 @@ class VersionParserTest extends \PHPUnit_Framework_TestCase
     public function simpleConstraints()
     {
         return array(
-            'match any'         => array('*',           new MultiConstraint(array())),
-            'match any/2'       => array('*.*',         new MultiConstraint(array())),
-            'match any/3'       => array('*.x.*',       new MultiConstraint(array())),
-            'match any/4'       => array('x.x.x.*',     new MultiConstraint(array())),
+            'match any'         => array('*',           new EmptyConstraint()),
+            'match any/2'       => array('*.*',         new EmptyConstraint()),
+            'match any/3'       => array('*.x.*',       new EmptyConstraint()),
+            'match any/4'       => array('x.x.x.*',     new EmptyConstraint()),
             'not equal'         => array('<>1.0.0',     new VersionConstraint('<>', '1.0.0.0')),
             'not equal/2'       => array('!=1.0.0',     new VersionConstraint('!=', '1.0.0.0')),
             'greater than'      => array('>1.0.0',      new VersionConstraint('>', '1.0.0.0')),