[Python-modules-team] Bug#857171: import of git can cause import failures of unrelated modules due to undefined variable

[Yaroslav Halchenko]

Package: python-git
Version: 2.1.0-1
Severity: critical
Tags: upstream patch

$> docker run -it --rm debian:stretch
root at 7f7cfee9f6fa:/# apt-get update -qqq; apt-get install -qqq -y python-h5py python-git
debconf: delaying package configuration, since apt-utils is not installed
(Reading database ... 6415 files and directories currently installed.)
Preparing to unpack .../perl-base_5.24.1-1_amd64.deb ...
...
done.
root at 7f7cfee9f6fa:/# python -c 'import git; import h5py'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/python2.7/dist-packages/h5py/__init__.py", line 60, in <module>
    from .tests import run_tests
  File "/usr/lib/python2.7/dist-packages/h5py/tests/__init__.py", line 15, in <module>
    from . import old, hl
  File "/usr/lib/python2.7/dist-packages/h5py/tests/old/__init__.py", line 4, in <module>
    from . import ( test_attrs,
  File "/usr/lib/python2.7/dist-packages/h5py/tests/old/test_group.py", line 41, in <module>
    fsencode(u"α")
  File "/usr/lib/python2.7/dist-packages/h5py/_hl/compat.py", line 68, in fsencode
    return filename.encode(encoding, errors)
  File "/usr/lib/python2.7/dist-packages/git/compat.py", line 180, in surrogateescape_handler
    decoded = replace_surrogate_encode(mystring)
  File "/usr/lib/python2.7/dist-packages/git/compat.py", line 207, in replace_surrogate_encode
    raise exc
NameError: global name 'exc' is not defined


Issue was reported and fixed upstream through a sequence of two PRs (heh) which
are compressed into a single small patch attached to this report.  This issue
already gave me notable pain, so quick update in stretch would be
appreciated!

here is a proof of it working:

root at 7f7cfee9f6fa:/usr/lib/python2.7/dist-packages# curl http://www.onerussian.com/tmp/exc_exception.patch | patch -p1
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  1338  100  1338    0     0   210k      0 --:--:-- --:--:-- --:--:--  217k
patching file git/compat.py
root at 7f7cfee9f6fa:/usr/lib/python2.7/dist-packages# cd /tmp
root at 7f7cfee9f6fa:/tmp# python -c 'import git; import h5py'
root at 7f7cfee9f6fa:/tmp# 


-- System Information:
Debian Release: 9.0
  APT prefers testing
  APT policy: (900, 'testing'), (600, 'unstable'), (300, 'experimental'), (100, 'unstable-debug')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.9.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages python-git depends on:
ii  git [git-core]  1:2.11.0-2
ii  git-core        1:2.11.0-2
ii  python-gitdb    2.0.0-2
pn  python:any      <none>

python-git recommends no packages.

Versions of packages python-git suggests:
ii  python-git-doc  2.1.0-1
ii  python-smmap    2.0.1-1

-- debconf-show failed
-------------- next part --------------
From: Yaroslav Halchenko <debian at onerussian.com>
Subject: Pass exc value to be re-raised 

Origin: https://github.com/gitpython-developers/GitPython/pull/598
        https://github.com/gitpython-developers/GitPython/pull/603
Bug-Debian: http://bugs.debian.org/
Bug-Ubuntu: https://launchpad.net/bugs/
Applied-Upstream: https://github.com/gitpython-developers/GitPython/commit/9ce2a4b235d2ebc38c3e081c1036e39bde9be036
Last-Update: 2017-03-08

diff --git a/git/compat.py b/git/compat.py
index a2403d6..b804585 100644
--- a/git/compat.py
+++ b/git/compat.py
@@ -177,7 +177,7 @@ def surrogateescape_handler(exc):
             # exception anyway after this function is called, even though I think
             # it's doing what it should. It seems that the strict encoder is called
             # to encode the unicode string that this function returns ...
-            decoded = replace_surrogate_encode(mystring)
+            decoded = replace_surrogate_encode(mystring, exc)
         else:
             raise exc
     except NotASurrogateError:
@@ -189,7 +189,7 @@ class NotASurrogateError(Exception):
     pass
 
 
-def replace_surrogate_encode(mystring):
+def replace_surrogate_encode(mystring, exc):
     """
     Returns a (unicode) string, not the more logical bytes, because the codecs
     register_error functionality expects this.