Preserve Trac comment numbers

[mkoeppe]

Currently the script converts Trac comments to GH Issue comments with a header like this:

Comment by @mkoeppe created at 2022-07-04 20:14:00

(sagemath/trac_to_gh#26 (comment))

It would be good to preserve the comment number, for the benefit of external links pointing to specific comments.
For example, we could just include the full original URL:

Comment by @mkoeppe created at 2022-07-04 20:14:00 (original: https://trac.sagemath.org/ticket/34110#comment:4)

Likewise, the script should show the original Trac URL of the ticket.

[dimpase]

ok, makes sense.

[kwankyu]

If we create links to trac in the converted issues and comments, then those links will be broken when trac is stopped someday. Is this okay?

[dimpase]

the idea is to either rewrite these links, or keep a readonly copy of trac around

[kwankyu]

Why create new links to trac if we rewrite them after migration?

I think it makes sense to embed the original comment number in the migrated comment but embedding a link to the original comment does not (if trac goes down someday)

[mkoeppe]

Separate from the question whether we want to display the trac links:

I think we need to keep a mapping (ticket_number, comment_number) -> issue_comment.url so that we can rewrite Trac links to specific comments

[kwankyu]

Yes.

[kwankyu]

After ticket-to-issue migration, would the issues (and comments therein) be editable? If yes, who will have the write permission? The original author?

[mkoeppe]

Yes, the original author of the issue or comment -- if we have a github account for them on file.

[mkoeppe]

Perhaps we can use markdown anchors in the issue comments. Here we refer to the next comment - comment 4711 using [comment 4711](#comment%3A4711)

[mkoeppe]

This is comment 4711: This comment has the anchor, created with <a id='comment:4711'></a>

[mkoeppe]

I'm writing these anchors out in 23a993f. Example: https://github.com/sagemath/trac_to_gh/blob/main/Issues-26xxx/26855.md#comment:5

Help welcome with rewriting links in "Replying to [comment:18 jdemeyer]:" etc. to markdown

[mkoeppe]

This is working well, thank you!

[mkoeppe]

Fixed by #45