trac-github-update/git-multimail: commit notification emails should use correct timestamp for sorting

[raimue (Rainer Müller)]

Commit notification mails currently always use the current time and date. When the delivery of the payload by the GitHub webhook is delayed, for example by a downtime of Trac and then clicking the "Redeliver" button on GitHub, commit mails may arrive that appear to be newer than other mails.

Unfortunately, the GitHub webhook payload does not include the timestamp when the push actually happened. Assuming that the rebasing on top of master happened closely before the push. The closest timestamp for sorting we could use would be the committer date of the latest commit that was pushed.

[raimue (Rainer Müller)]

This will require patching git-multimail, as it does not allow to overwrite the time and date at the moment:

• ​https://github.com/git-multimail/git-multimail/blob/87a7070/git-multimail/git_multimail.py#L3571-L3590

[raimue (Rainer Müller)]

Turns out this is easier than thought in Python with monkey patching:

• ​https://github.com/macports/trac.macports.org/pull/2/commits/9464d9d4872de9b4d170f0d6781570616e14ac87

[raimue (Rainer Müller)]

In 5b6df91/trac.macports.org:

trac-github-update: fake date and time of emails

Closes: #52890