doc/todo/web_reversion.mdwn



Goal: Web interface to allow reverting of changes.
Interface:
At least at first, it will be exposed via the recentchanges
page, with revert icons next to each change. We may want a dynamic
per-page interface that goes back more than 100 changes later.
Limiting assumptions:

No support for resolving conflicts in reverts; such a revert would just
fail and not happen.
No support for reset-to-this-point; initially the interface would only
revert a single commit, and if a bunch needed to go, the user would have
to drive that one at a time.

Implementation plan:

rcs_revert hook that takes a revision to revert.
CGI: do=revert&rev=foo
recentchanges plugin adds above to recentchanges page
prompt user to confirm (to avoid spiders doing reverts),
check that user is allowed to make the change, commit reversion,
and refresh site.

Peter Gammie has done an initial implementation of the above.
[[!template id=gitbranch branch=peteg/revert author="[[peteg]]"]]


It is on a separate branch now. --[[peteg]]


Review: --[[Joey]]
The revert commit will not currently say what web user did the revert.
This could be fixed by doing a --no-commit revert first and then using
rcs_commit_staged.

Fixed, I think. --[[peteg]]

So I see one thing I completly forgot about is check_canedit. Avoiding users
using reverting to make changes they would normally not be allowed to do is
tricky. I guess that a easy first pass would be to only let admins do it.
That would be enough to get the feature out there..
I'm thinking about having a rcs_preprevert. It would take a rev and look
at what changes reverting it would entail, and return the same data
structure that rcs_recieve does. This could be done by using git revert --no-commit, and then examining the changes, and then git reset to drop
them.
Then the code that is currently in IkiWiki/Receive.pm, that calls
check_canedit and check_canremove to test the change, can be
straightforwardly refactored out, and used for checking reverts too.
(The data from rcs_preprevert could also be used for a confirmation
prompt -- it doesn't currently include enough info for diffs, but at
least could have a list of changed files.)
Note that it's possible for a git repo to have commits that modify wiki
files in a subdir, and code files elsewhere. rcs_preprevert should
detect changes outside the wiki dir, and fail, like rcs_receive does.