Make the module autoloader to register class aliases for the classes that are...

Make the module autoloader to register class aliases for the classes that are migrated to namespaces, so that they are still accessible via the old name. This keeps everything working while migrating the classes.

lib/_autoload_modules.php

@@ -12,6 +12,8 @@
  * Autoload function for SimpleSAMLphp modules following PSR-0.
  *
  * @param string $className Name of the class.
+ *
+ * TODO: this autoloader should be removed once everything has been migrated to namespaces.
  */
 function SimpleSAML_autoload_psr0($className)
 {
@@ -22,18 +24,30 @@ function SimpleSAML_autoload_psr0($className)
     }
 
     $modNameEnd = strpos($className, '_', $modulePrefixLength);
-    $module = substr($className, $modulePrefixLength, $modNameEnd - $modulePrefixLength);
-    $moduleClass = substr($className, $modNameEnd + 1);
+    $module     = substr($className, $modulePrefixLength, $modNameEnd - $modulePrefixLength);
+    $path       = explode('_', substr($className, $modNameEnd + 1));
 
     if (!SimpleSAML_Module::isModuleEnabled($module)) {
         return;
     }
 
-    $file = SimpleSAML_Module::getModuleDir($module).'/lib/'.str_replace('_', '/', $moduleClass).'.php';
-
+    $file = SimpleSAML_Module::getModuleDir($module).'/lib/'.join('/', $path).'.php';
     if (file_exists($file)) {
         require_once($file);
     }
+
+    if (!class_exists($className, false)) {
+        // the file exists, but the class is not defined. Is it using namespaces?
+        $nspath = join('\\', $path);
+        if (class_exists('SimpleSAML\Module\\'.$module.'\\'.$nspath)) {
+            // the class has been migrated, create an alias and warn about it
+            SimpleSAML_Logger::warning(
+                "The class '$className' is now using namespaces, please use 'SimpleSAML\\Module\\$module\\".
+                "$nspath' instead."
+            );
+            class_alias("SimpleSAML\\Module\\$module\\$nspath", $className);
+        }
+    }
 }