Issue 38020: os.path.realpath crashes in Windows Store package [proxy]

The Wayback Machine - https://web.archive.org/web/20210523042214/https://bugs.python.org/issue38020

Issue38020

classification

Title:	os.path.realpath crashes in Windows Store package
Type:	crash	Stage:	resolved
Components:	Windows	Versions:	Python 3.9, Python 3.8

process

Status:	closed	Resolution:	fixed
Dependencies:		Superseder:
Assigned To:	steve.dower	Nosy List:	lukasz.langa, miss-islington, paul.moore, steve.dower, tim.golden, zach.ware
Priority:	release blocker	Keywords:	3.8regression, patch

Created on 2019-09-03 18:28 by steve.dower, last changed 2019-09-03 20:16 by steve.dower. This issue is now closed.

Messages (4)
msg351094 - (view)	Author: Steve Dower (steve.dower) *	Date: 2019-09-03 18:28
When installed via the Store, "python3.8 -c 'import sysconfig'" crashes hard. So far, I've discovered it's inside an os.path.realpath() call, and appears to be a refcounting issue (double DECREF I think), but haven't gotten any further yet. I'm looking into it.
msg351095 - (view)	Author: Steve Dower (steve.dower) *	Date: 2019-09-03 18:45
I forgot to initialize the result object in readlink() on Windows, and so when we hit the failure path it returns garbage. Attempting to DECREF that garbage fails. The call to readlink() fails in the Store app because sys.executable is not a readable link. It should fail in most cases anyway, but apparently outside of the app container the stack is NULL here.
msg351100 - (view)	Author: Steve Dower (steve.dower) *	Date: 2019-09-03 19:50
New changeset 993ac92418839427d4068d6ae8e618b06b5d9294 by Steve Dower in branch 'master': bpo-38020: Fixes crash in os.readlink() on Windows (GH-15663) https://github.com/python/cpython/commit/993ac92418839427d4068d6ae8e618b06b5d9294
msg351102 - (view)	Author: miss-islington (miss-islington)	Date: 2019-09-03 20:13
New changeset 54dac6c0f4fa24d03025c45899ee7c5f2a4c367e by Miss Islington (bot) in branch '3.8': bpo-38020: Fixes crash in os.readlink() on Windows (GH-15663) https://github.com/python/cpython/commit/54dac6c0f4fa24d03025c45899ee7c5f2a4c367e

History
Date	User	Action	Args
2019-09-03 20:16:14	steve.dower	set	status: open -> closed resolution: fixed stage: patch review -> resolved
2019-09-03 20:13:46	miss-islington	set	nosy: + miss-islington messages: + msg351102
2019-09-03 19:51:10	miss-islington	set	pull_requests: + pull_request15330
2019-09-03 19:50:56	steve.dower	set	messages: + msg351100
2019-09-03 18:49:05	steve.dower	set	keywords: + patch stage: test needed -> patch review pull_requests: + pull_request15328
2019-09-03 18:45:57	steve.dower	set	messages: + msg351095
2019-09-03 18:28:55	steve.dower	create