[pywin32-bugs] [ pywin32-Bugs-3519214 ] Error handling in win32gui.GetClassName

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Bugs item #3519214, was opened at 2012-04-18 11:10
Message generated for change (Settings changed) made by rupole
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Category: win32
Group: None
>Status: Closed
>Resolution: Fixed
Priority: 5
Private: No
Submitted By: David Nelson (dlnelson-logger)
Assigned to: Nobody/Anonymous (nobody)
Summary: Error handling in win32gui.GetClassName

Initial Comment:
When the handle passed to win32gui.GetClassName is invalid (perhaps because the window was previously destroyed), it calls PyWin_SetAPIError, but then returns the empty string (instead of NULL).  This causes the exception to be raised some time later depending on the following code.

At an interactive interpreter, I get:

>>> win32gui.GetClassName(0)
''
>>>
pywintypes.error: (1400, 'GetClassName', 'Invalid window handle.')
>>>

At the second prompt, I just press enter.

If pyreadline is installed, a full traceback from somewhere in pyreadline is printed immediately after the first line.

I suspect the problem is in win32/src/win32gui.i on line 5999 (as of 6e918dcbc8c7), which should return PyWin_SetAPIError (or explicitly return NULL).

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>Comment By: Roger Upole (rupole)
Date: 2012-04-20 01:43

Message:
Fixed in changeset 4196.

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You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=551954&aid=3519214&group_id=78018