diff mercurial/demandimport.py @ 29748:14f077f7519a

demandimport: import sub-module relatively as expected (issue5208)

Before this patch, importing sub-module might (1) fail or (2) success
but import incorrect module, because demandimport tries to import
sub-module with level=-1 (on Python 2.x) or level=0 (on Python 3.x),
which is default value of "level" argument at construction of
"_demandmod" proxy object.

  (1) on Python 3.x, importing sub-module always fails to import
      existing sub-module

  (2) both on Python 2.x and 3.x, importing sub-module might import
      same name module on root level unintentionally

      On Python 2.x, existing sub-module is prior to this unexpected
      module. Therefore, this problem hasn't appeared.

To import sub-module relatively as expected, this patch specifies "1"
as import level explicitly at construction of "_demandmod" proxy
object for sub-module.

--- a/mercurial/demandimport.py	Sat Aug 06 15:00:34 2016 -0700
+++ b/mercurial/demandimport.py	Sat Aug 06 22:24:33 2016 +0900
@@ -117,7 +117,8 @@
                 if '.' in p:
                     h, t = p.split('.', 1)
                 if getattr(mod, h, nothing) is nothing:
-                    setattr(mod, h, _demandmod(p, mod.__dict__, mod.__dict__))
+                    setattr(mod, h, _demandmod(p, mod.__dict__, mod.__dict__,
+                                               level=1))
                 elif t:
                     subload(getattr(mod, h), t)
 
@@ -210,8 +211,8 @@
             mod = rootmod
             for comp in modname.split('.')[1:]:
                 if getattr(mod, comp, nothing) is nothing:
-                    setattr(mod, comp,
-                            _demandmod(comp, mod.__dict__, mod.__dict__))
+                    setattr(mod, comp, _demandmod(comp, mod.__dict__,
+                                                  mod.__dict__, level=1))
                 mod = getattr(mod, comp)
             return mod