Ensure detected extensions have valid package names

src/Composer/Repository/PlatformRepository.php

@@ -70,7 +70,8 @@ class PlatformRepository extends ArrayRepository
                 $version = $versionParser->normalize($prettyVersion);
             }
 
-            $ext = new CompletePackage('ext-'.$name, $version, $prettyVersion);
+            $packageName = $this->buildPackageName($name);
+            $ext = new CompletePackage($packageName, $version, $prettyVersion);
             $ext->setDescription('The '.$name.' PHP extension');
             parent::addPackage($ext);
         }
@@ -159,4 +160,10 @@ class PlatformRepository extends ArrayRepository
             parent::addPackage($hhvm);
         }
     }
+
+
+    private function buildPackageName($name)
+    {
+        return 'ext-' . str_replace(' ', '-', $name);
+    }
 }