Fix stdin_has_data()

[bdrung]

When calling gitlint in a custom git commit hook on a gitlab server, stdin_has_data() will always return True regardless whether gitlint is called directly or text is piped into it. To reproduce you can call this
script:

#!/usr/bin/python3

import sys
import stat
import os

if sys.stdin.isatty():
    print("Input comes from tty.")
else:
    print("Input doesn't come from tty.")

mode = os.fstat(sys.stdin.fileno()).st_mode
if stat.S_ISFIFO(mode):
    print("stdin is piped")
elif stat.S_ISREG(mode):
    print("stdin is redirected")
else:
    print("stdin is terminal")

On my server it prints:

Input doesn't come from tty.
stdin is terminal

stdin should only be read if the user uses a pipe or a redirect to pass data in.

[jorisroovers]

I got similar feedback in #42 after I thought I fixed it with the last release. I need to make some more time to play with this, because this is a fundamental part of gitlint. I want to understand and test it properly myself before merging a PR related to it.

I don't know when I have time, but I'm going to try and make some in the next few weeks since this is a fairly big issue. Appreciate your patience!

I think the following should work as a temp workaround: git log -1 --pretty=%B | gitlint

[bdrung]

My workaround is to use this patch. 😉 So there is no hurry on my side.

Some test cases you can use:

$ echo | gitlint
$ gitlint < textfile
$ gitlint

[pbregener]

BTW: The workaround you described @jorisroovers (piping the commit message body into gitlint) doesn't work if you have rules regarding author names and/or email addresses.

[pbregener]

As mentioned in #42, the "has-STDIN-data-check" doesn't work inside certain Jenkins and GitLab CI environments.
Unfortunately, this patch doesn't fix that problem, either (tested on GitLab CI).

[bdrung]

@pbregener Have you tested my proposed patch? Can you comment how you configured GitLab CI? I am using this patch with GitLab.

[pbregener]

Yes. I am running gitlint in a pretty standard GitLab CI config using the Docker executor and the latest gitlab-runner (v10.4.0).

[bdrung]

v10.4.0 does not contain the proposed patch from this pull request. Can you apply the patch from this pull request and try again? How do you invoke gitlint?

[pbregener]

I applied the patch from this pull request to gitlint. I'm not sure what the gitlab-runner version has to do with this. I invoke gitlint from a bash script, which is linked in the project's .gitlab-ci.yml.

[pbregener]

You mentioned that you use it in GitLab with a commit hook which will be an entirely different thing.

[jorisroovers]

Closing this out, this got fixed in 5c93309. More context in #42.