671625 - AddDefaultGateway does not check gateway for validity

Status: RESOLVED FIXED

(Other Applications Graveyard :: PyXPCOM, defect)

Description

[Mook (work)]

Attachment: check weak reference for liveness

AddDefaultGateway does not ensure that the gateway is still alive, just that the object has an attribute of the right name. This means that, for a python object O implementing interface I, if you
1) Get a O -> I wrapper,
2) Release it (so the wrapper dies),
3) Get a new O -> I wrapper,
O will still think it has a default gateway (that is long dead), instead of the new one.

See attached patch.

For more concrete STR, grab a debug build of Komodo, set it to open nothing on startup (not even the start page), then restart, and open a recent project from the menu.  It aborts in PyG_Base::AutoWrapPythonInstance with a koProject with "Auto-wrapped object didn't get a default gateway!".

Comment 1

[Todd Whiteman]

Is there a test case that can be added to check this?

Comment 2

[Mook (work)]

Attachment: now with a test

Turns out it involves wrapping the object during repr() (in the koProject case, ultimately it tried to add itself as an observer to the pref observer service in __repr__).

Comment 3

[Todd Whiteman]

Comment on attachment 546816 [details] [diff] [review]
now with a test

Committed in:
  http://hg.mozilla.org/pyxpcom/rev/b2c1ad354b91

Comment 4

[Todd Whiteman]

There was a missing "PyErr_Clear();" for the PyObject_GetAttrString call, to clear the exception when there was no "PyXPCOM_szDefaultGatewayAttributeName" attribute set on the object.

Added in change:
  http://hg.mozilla.org/pyxpcom/rev/2cce3102916e