Support for 'prefer-source' config setting, refs #553

src/Composer/Command/ConfigCommand.php

@@ -255,6 +255,10 @@ EOT
                 function ($val) { return in_array($val, array('true', 'false', '1', '0'), true); },
                 function ($val) { return $val !== 'false' && (bool) $val; }
             ),
+            'prefer-source' => array(
+                function ($val) { return in_array($val, array('true', 'false', '1', '0'), true); },
+                function ($val) { return $val !== 'false' && (bool) $val; }
+            ),
             'notify-on-install' => array(
                 function ($val) { return in_array($val, array('true', 'false', '1', '0'), true); },
                 function ($val) { return $val !== 'false' && (bool) $val; }

src/Composer/Config.php

@@ -22,6 +22,7 @@ class Config
     public static $defaultConfig = array(
         'process-timeout' => 300,
         'use-include-path' => false,
+        'prefer-source' => false,
         'notify-on-install' => true,
         'github-protocols' => array('git', 'https', 'http'),
         'vendor-dir' => 'vendor',