Index: modules/system/system.test
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.test,v
retrieving revision 1.8
diff -u -r1.8 system.test
--- modules/system/system.test	29 Jun 2008 11:39:38 -0000	1.8
+++ modules/system/system.test	30 Jun 2008 00:58:21 -0000
@@ -186,12 +186,15 @@
     $this->drupalPost('admin/settings/ip-blocking', $edit, t('Save'));
     $this->assertText(t('Please enter a valid IP address.'));
 
-    // Submit your own IP address. This fails, although it works when testing manually.
-     // TODO: on some systems this test fails due to a bug or inconsistency in cURL.
-     // $edit = array();
-     // $edit['ip'] = ip_address();
-     // $this->drupalPost('admin/settings/ip-blocking', $edit, t('Save'));
-     // $this->assertText(t('You may not block your own IP address.'));
+    // Submit your own IP address.
+    $edit = array();
+    // We assume during the tests that the base URL points back to ourself.
+    // In that case, because we are hitting the loopback interface,
+    // the client IP address will in fact be the target IP address.
+    $parsed = parse_url($GLOBALS['base_url']);
+    $edit['ip'] = gethostbyname($parsed['host']);
+    $this->drupalPost('admin/settings/ip-blocking', $edit, t('Save'));
+    $this->assertText(t('You may not block your own IP address.'));
   }
 }