As a user of Gerrit, I'd like a bot that resolves Gerrit comments when another change has merged

In API-reviews, in particular, we link Gerrit changes fixing an issue found during review in a comment at the end of the thread. Example: https://codereview.qt-project.org/c/qt/qtbase/+/565638/comment/04a4bd24_9af6500c/

We then manually resolve the comments with a "Merged" comment when the linked change has integrated into the desired target branch.

It would make everyone's job much easier, and foster this kind of cross-linking of Gerrit changes, if a bot would do the closing.

I'm thinking of a light-weight syntax for linking the changes that cause a bot to go in and resolve the comment with a Message "Merged to <branch> as <sha1>.".

Example syntax:

Bot: <url> [<target branch>]

If <target branch> is omitted, default to dev or master, depending on what the particular project uses as it's HEAD-most branch name.

Example for the above comment thread:

Bot: https://codereview.qt-project.org/c/qt/qtbase/+/582924 6.8

Obvious open questions:

• Add messages (but not resolve comment) as change gets merged into non-target branches?
• How to deal with reverts?
• ... with abandoning?
• ... with user unresolving of the comment thread?
• ... with one comment thread spawning multiple changes?
• ... with contradictory Bot: commands in the thread (last one wins? AND together?)

But first, we should look into whether we can principally get such a bot going.