Issue #2200185 by BTMash, damiankloip: Router table is not cleared when modules are uninstalled.

core/lib/Drupal/Core/Extension/ModuleHandler.php

@@ -759,6 +759,9 @@ class ModuleHandler implements ModuleHandlerInterface {
       watchdog('system', '%module module uninstalled.', array('%module' => $module), WATCHDOG_INFO);
 
       $schema_store->delete($module);
+
+      // Make sure any route data is also removed for this module.
+      \Drupal::service('router.dumper')->dump(array('provider' => $module));
     }
     drupal_get_installed_schema_version(NULL, TRUE);
 

core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php

@@ -192,4 +192,13 @@ class RouterTest extends WebTestBase {
 
     $this->assertRaw('abcde', 'Correct body was found.');
   }
+
+  /**
+   * Tests that routes no longer exist for a module that has been uninstalled.
+   */
+  public function testRouterUninstall() {
+    \Drupal::moduleHandler()->uninstall(array('router_test'));
+    $route_count = \Drupal::database()->query('SELECT COUNT(*) FROM {router} WHERE provider = :provider', array(':provider' => 'router_test'))->fetchField();
+    $this->assertEqual(0, $route_count, 'All router_test routes have been removed on uninstall.');
+  }
 }