[bug] Commenting on a non-head git changeset fails with TypeError in notification email (0.7.0, still in tip)

[橋本 憲一]

Hi,

Adding a comment to a git changeset that is not a branch head fails with HTTP 500, and the comment is not saved.

Version: Kallithea 0.7.0 (Python 3.11). The same code is still present in tip.

Steps to reproduce:
1. In a git repository, open a changeset that is not the head of any branch (for example, the parent of the master head).
2. Add a general (not inline) comment.

Result: HTTP 500. The error log shows:

  kallithea/model/comment.py, in create_notification
  kallithea/model/notification.py, in get_email_tmpl
      return email_template.render_unicode(**_kwargs)
  mako/util.py, in getvalue
      return self.delim.join(self.data)
  TypeError: sequence item 16: expected str instance, NoneType found

Cause: in kallithea/lib/vcs/backends/git/changeset.py, GitChangeset.branch returns None unless the commit is a branch head. kallithea/model/comment.py passes it through unchanged ('branch': cs.branch), and templates/email/changeset_comment.txt renders it with ${branch|n}, so rendering fails and the whole comment request is rolled back. Commenting on a branch-head changeset works.

Possible fix: pass a string, for example 'branch': cs.branch or '' (or ', '.join(cs.branches)), or guard the value in changeset_comment.txt / changeset_comment.html.

Regards,