mercurial/extensions.py

--- a/mercurial/extensions.py	Sat Jun 24 02:39:13 2017 +0900
+++ b/mercurial/extensions.py	Fri Jun 23 10:59:05 2017 -0700
@@ -257,7 +257,9 @@
     '''
 
     if extension in _extensions:
-        callback(loaded=True)
+        # Report loaded as False if the extension is disabled
+        loaded = (_extensions[extension] is not None)
+        callback(loaded=loaded)
     else:
         _aftercallbacks.setdefault(extension, []).append(callback)