Blank lines after title cause gitlint to ignore missing body (B6)

[dan-cohn-sabre]

I've discovered an unusual problem. We have folks creating commits with only a title, and gitlint isn't complaining. There's nothing in the .gitlint file to disable this check.

What I've found through testing is that a title followed by 2 or more blank lines passes gitlint even though the message contains no body.

Here's an example with debug:

$ gitlint --debug --msg-filename ~/COMMIT_EDITMSG run-hook
DEBUG: gitlint.cli To report issues, please visit https://github.com/jorisroovers/gitlint/issues
DEBUG: gitlint.cli Platform: Linux-5.4.39-linuxkit-x86_64-with-centos-8.2.2004-Core
DEBUG: gitlint.cli Python version: 3.6.8 (default, Apr 16 2020, 01:36:27) 
[GCC 8.3.1 20191121 (Red Hat 8.3.1-5)]
DEBUG: gitlint.git ('--version',)
DEBUG: gitlint.cli Git version: git version 2.27.0
DEBUG: gitlint.cli Gitlint version: 0.14.0
DEBUG: gitlint.cli GITLINT_USE_SH_LIB: [NOT SET]
DEBUG: gitlint.cli DEFAULT_ENCODING: UTF-8
DEBUG: gitlint.cli Configuration
config-path: /home/sabre2/src/sabre2/.gitlint
[GENERAL]
extra-path: None
contrib: ['contrib-title-conventional-commits']
ignore: 
ignore-merge-commits: True
ignore-fixup-commits: True
ignore-squash-commits: True
ignore-revert-commits: True
ignore-stdin: False
staged: False
verbosity: 3
debug: True
target: /home/sabre2/src/sabre2
[RULES]
  I1: ignore-by-title
     ignore=all
     regex=None
  I2: ignore-by-body
     ignore=all
     regex=None
  I3: ignore-body-lines
     regex=None
  T1: title-max-length
     line-length=72
  T2: title-trailing-whitespace
  T6: title-leading-whitespace
  T3: title-trailing-punctuation
  T4: title-hard-tab
  T5: title-must-not-contain-word
     words=WIP
  T7: title-match-regex
     regex=None
  T8: title-min-length
     min-length=5
  B1: body-max-line-length
     line-length=80
  B5: body-min-length
     min-length=20
  B6: body-is-missing
     ignore-merge-commits=True
  B2: body-trailing-whitespace
  B3: body-hard-tab
  B4: body-first-line-empty
  B7: body-changed-file-mention
     files=
  B8: body-match-regex
     regex=None
  M1: author-valid-email
     regex=[^@ ]+@[^@ ]+\.[^@ ]+
  CT1: contrib-title-conventional-commits
     types=fix,feat,chore,docs,style,refactor,perf,test,revert,ci,build

gitlint: checking commit message...
DEBUG: gitlint.cli Using --msg-filename.
DEBUG: gitlint.git ('config', '--get', 'core.commentchar')
DEBUG: gitlint.cli Linting 1 commit(s)
DEBUG: gitlint.lint Linting commit [SHA UNKNOWN]
DEBUG: gitlint.lint Commit Object
--- Commit Message ----
feat: test



--- Meta info ---------
Author: None <None>
Date:   None
is-merge-commit:  False
is-fixup-commit:  False
is-squash-commit: False
is-revert-commit: False
Branches: []
Changed Files: []
-----------------------
DEBUG: gitlint.cli Exit Code = 0
gitlint: OK (no violations in commit message)

I updated to version 0.15.0 and had the same problem.

[jorisroovers]

Good find, thanks for opening the issue!

Seems such a basic issue that I'm surprised it was never caught before. I think that's probably because git commit prunes trailing newlines (I believe by default).

In any case, I was able to reproduce this like so:

# These work as expected
echo "foo" | gitlint
echo "foo\n" | gitlint

# These don't, they're not showing the B6 rule
echo "foo\n\n" | gitlint
echo "foo\n\n\n" | gitlint

Will be double checking the fix in #179 shortly, but looks pretty good.