Index: includes/install.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/install.inc,v
retrieving revision 1.90
diff -u -r1.90 install.inc
--- includes/install.inc	12 May 2009 18:08:42 -0000	1.90
+++ includes/install.inc	14 May 2009 17:01:07 -0000
@@ -539,6 +539,7 @@
     module_invoke($module, 'install');
     $versions = drupal_get_schema_versions($module);
     drupal_set_installed_schema_version($module, $versions ? max($versions) : SCHEMA_INSTALLED);
+    watchdog('system', '%module module installed.', array('%module' => $module), WATCHDOG_INFO);
     return TRUE;
   }
 }
Index: modules/system/system.test
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.test,v
retrieving revision 1.42
diff -u -r1.42 system.test
--- modules/system/system.test	12 May 2009 18:08:43 -0000	1.42
+++ modules/system/system.test	14 May 2009 17:01:08 -0000
@@ -118,6 +118,7 @@
 
     // Check that hook_modules_installed and hook_modules_enabled hooks were invoked and check tables.
     $this->assertText(t('hook_modules_installed fired for aggregator'), t('hook_modules_installed fired.'));
+    $this->assertLogMessage('system', "%module module installed.", array('%module' => 'aggregator'), WATCHDOG_INFO);
     $this->assertText(t('hook_modules_enabled fired for aggregator'), t('hook_modules_enabled fired.'));
     $this->assertModules(array('aggregator'), TRUE);
     $this->assertTableCount('aggregator', TRUE);