Allow parsing of stability modifiers combined with multi-constraints

src/Composer/Package/Version/VersionParser.php

@@ -234,6 +234,13 @@ class VersionParser
 
     private function parseConstraint($constraint)
     {
+        if (preg_match('{^([^,\s]+?)@('.implode('|', array_keys(BasePackage::$stabilities)).')$}i', $constraint, $match)) {
+            $constraint = $match[1];
+            if ($match[2] !== 'stable') {
+                $stabilityModifier = $match[2];
+            }
+        }
+
         if (preg_match('{^[x*](\.[x*])*$}i', $constraint)) {
             return array();
         }
@@ -274,6 +281,10 @@ class VersionParser
             try {
                 $version = $this->normalize($matches[2]);
 
+                if (!empty($stabilityModifier) && $this->parseStability($version) === 'stable') {
+                    $version .= '-' . $stabilityModifier;
+                }
+
                 return array(new VersionConstraint($matches[1] ?: '=', $version));
             } catch (\Exception $e) {}
         }

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

@@ -249,6 +249,15 @@ class VersionParserTest extends \PHPUnit_Framework_TestCase
         $this->assertSame((string) $multi, (string) $parser->parseConstraints('>2.0,<=3.0'));
     }
 
+    public function testParseConstraintsMultiWithStabilities()
+    {
+        $parser = new VersionParser;
+        $first = new VersionConstraint('>', '2.0.0.0');
+        $second = new VersionConstraint('<=', '3.0.0.0-dev');
+        $multi = new MultiConstraint(array($first, $second));
+        $this->assertSame((string) $multi, (string) $parser->parseConstraints('>2.0@stable,<=3.0@dev'));
+    }
+
     /**
      * @dataProvider failingConstraints
      * @expectedException UnexpectedValueException