[ python-Bugs-1029475 ] PEP 302 loader not carried through by reload function

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Bugs item #1029475, was opened at 2004-09-16 20:35
Message generated for change (Comment added) made by pje
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Category: Python Interpreter Core
>Group: Python 2.3
>Status: Closed
>Resolution: Fixed
Priority: 5
Submitted By: Stephen Haberman (filitov)
Assigned to: Phillip J. Eby (pje)
Summary: PEP 302 loader not carried through by reload function

Initial Comment:
This is based on bug 856103 "reload() fails with
modules from zips", but only a fix for the PEP 302
loaders not being used in reload.

There are other issues with reloading zip files,
specifically when the size of the zip changes, new
buffers are not created, but that is a separate issue
and dealt with in bug 856103 instead of here.

----

This patch just modifies import.c's
PyImport_ReloadModule to use a loader argument to
find_module and load_module.

A few things to note:

1) After my original 856103 patch was made, the path
parameter to find_module now has to be non null. This
path variable was only being set in the subname != NULL
case off of the parent, so I copied the logic to get
the path off of the existing module in the subname ==
NULL case. This seems to work.

2) I was fairly sure with my original 856103 patch,
"reload(mod)" and then "mod.newFunction()" would work.
But now the test case has to do "mod = reload(mod)" for
the "newFunction()" call to work.

I do not know whether this is related to something in
this patch or not.


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>Comment By: Phillip J. Eby (pje)
Date: 2004-09-23 05:23

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Fixed for 2.4 and the 2.3 maintenance branch, using simpler
test code, and adding a missing Py_XDECREF to the C change.

PEP 302 has also been updated to point out that loaders must
use the existing module in sys.modules, if present, and the
TestImporter in test_importhooks has been changed to do
this.  zipimport, however, does not do this, and that is a
problem that still needs fixing (see bug #856103 for some
other zipimport+reload issues).


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Comment By: Stephen Haberman (filitov)
Date: 2004-09-16 22:38

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You're right, the path = m.__path__ stuff was all wrong. I
was not initializing path to NULL in the first place. I've
attached the updated patch.

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Comment By: Phillip J. Eby (pje)
Date: 2004-09-16 21:00

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Hi Stephen.  I don't understand why 'path' has to be
non-null.  Not only that, but if it *is* null and the module
has no __path__, your patch is still going to pass in a null
path.  So I'm confused.  How did you discover the problem?

Similarly, I'm confused as to why 'mod=reload(mod)' would be
necessary now, but wasn't before.  There have been no
changes that I see in test_importhooks that would cause
that.  What was your testing methodology for this?


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Comment By: Stephen Haberman (filitov)
Date: 2004-09-16 20:45

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Okay, this one is actually the patch, not the test case
itself. Sheesh.

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Comment By: Stephen Haberman (filitov)
Date: 2004-09-16 20:41

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Attached the patch with a better test case.

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Comment By: Stephen Haberman (filitov)
Date: 2004-09-16 20:37

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Trying to upload the patch.

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