`universal_newlines` is not respected if git process times out

[x-santiaga-x]

In Git.execute if kill_check.isSet(): then stderr_value will be encoded to bytes even if universal_newlines is set.

[Byron]

Can you be more specific as to allow a PR to be created? In that moment I request a change of the subject as well.
This issue isn't currently actionable.

This issue will be reopened once the requested information was provided.

[x-santiaga-x]

If we run operation long enough to be killed after timeout and use universal_newlines set to True as this

from git.cmd import Git
g = Git(r'/path/to/repo')
g.rev_list('HEAD', kill_after_timeout=1e-6, universal_newlines=True)

script execution stopped with traceback

Traceback (most recent call last):
  File "../src/test.py", line 28, in <module>
    g.rev_list('HEAD', kill_after_timeout=1e-6, universal_newlines=True)
  File "/venv/path/lib64/python3.6/site-packages/git/cmd.py", line 542, in <lambda>
    return lambda *args, **kwargs: self._call_process(name, *args, **kwargs)
  File "/venv/path/lib64/python3.6/site-packages/git/cmd.py", line 1006, in _call_process
    return self.execute(call, **exec_kwargs)
  File "/venv/path/lib64/python3.6/site-packages/git/cmd.py", line 789, in execute
    if stderr_value.endswith(newline):
TypeError: endswith first arg must be bytes or a tuple of bytes, not str

because stderr_value is an error message about timeout decoded to bytes, but with universal_newlines = True newline is str, not bytes.

[Byron]

Thanks a lot! This looks like the logic here needs to adhere to the universal newlines flag. Would you be able to submit a PR for a fix?