On Fri, 2009-12-04, Daniel Näslund wrote:
> Hi Julian & Stefan!
>
> Some comments inline. A new classfication at the end and some initial
> thoughts about API changes. Early I know but I want to code, doing all
> this thinking is boring :-).
>
> Is it possible to just do resolution for files as a first stage? I mean
> both spec and implementation.
Kind of... but you have to consider how each of your design concepts
will extend to cover directories and directory trees, so that you get a
design that will extend well.
(I haven't studied the rest of your message - your new classification -
yet.)
- Julian
> On Wed, Dec 02, 2009 at 12:57:31PM +0000, Julian Foad wrote:
> > Stefan Sperling wrote:
> > What I meant was that, in this file "resolution.txt", I listed other
> > possibilities for resolutions that might be useful, and we can document
> > those somewhere (on a web site) for users to follow manually (e.g. "copy
> > X to Y, revert X, apply the patch you saved in step 1").
> >
> > We can also provide interactive menu options for making svn do some of
> > those things, if we want to.
> >
> > I didn't mean we should provide interactive menu options that just print
> > a list of instructions.
>
> Should have figured. It seemed a bit odd.
>
> > > What should definitely be there is a 'postpone' option, meaning "leave
> > > the conflict markers in place and leave the WC in this state, I'll deal
> > > with it manually". But I don't think the option needs to explain anything
> > > or suggest ways to go about solving the conflict. What if we get it
> > > wrong and give wrong advice? Users won't be happy. We'll have to rely
> > > on them to engage their brain instead.
> >
> > Yup. (Though "What if we get it wrong" is a dubious argument.)
>
> Noted. And it's so easy to write. I like that option.
>
> > > We might also want to provide an option to view the revision log of
> > > any file or its parent directory from within the menu, so people can
> > > dig in the history without having to open another terminal etc.
> >
> > Heh, sure we could, and we could make the log history navigable and ...
> > but that's more of a UI task that TortoiseSvn and RapidSvn and VisualSvn
> > can do well, and svn can never do well.
>
> If I understood Bert correctly, we're supposed to be able to deal with
> the conflicts even after the up/sw/merge has run. [1] No need to make
> things to interactive then.
>
> > > > Categories of conflicts
> > > > ========================
> > > > 1. Locale add, incoming add
> > > > 2. Locale del, incoming del
> > > > 3. Locale del, incoming edit
> > > > 4. Locale edit, incoming del
> >
> > It's also worth thinking about moves as different from delete-and-add,
> > although we are not yet ready to detect them properly.
>
> No svn_wc_conflict_reason_t or svn_wc_conflict_action_t for that yet. I
> will have to wait.
>
> > > > 1. Locale add, incoming add
> > > > ============================
> [...]
> > > > - I was doing roughly the same thing but the item is a bit different.
> > > > -> merge the two items -> manual 2-way merge (or 3-way if both are
> > > > w/hist and it's the same copy-from source) -> MERGE.
> > >
> > > Possible options after the merge (based on OpenBSD's sysmerge which
> > > merges configuration files after a system update):
> > >
> > > - edit the merged file again
> > > - install the merged file in WORKING
>
> svn_wc_conflict_choose_merged?
>
> > > - view a diff between a WORKING file and the merged file
> > > - view a diff between a BASE file and the merged file
> > > - re-do the merge
> > > - view the merged file
> > > - discard the merged file and go back to previous menu
>
> When looking in svn_cl__conflict_handler() I get a lot of guidance on
> how to write theese. A bit unsure about the 're-do the merge' option but
> that's for later.
>
> > > > THEIRS
> > > > --------
> > > > Replace <file> in WORKING with the new BASE that comes in during the
> > > > update.
> > > > *Problems*: We may need to undo a local move or copy operation with
> > > > destination <file>.
> > >
> > > Let's ignore existing copies of the file for now.
>
> Ok, that simplifies things.
>
> > > We just need to offer an option to either keep the current WORKING
> > > file in WORKING or put the new BASE file in WORKING. Even if the local
> > > add was the destination of a copy, there are only those two options.
> > >
> > > We don't need to worry about destroying anything. Maybe keep an
> > > unversioned
> > > backup of whichever file was overwritten.
>
> Keep a backup... I will need to think more about that.
>
> >
> > > > THEIRS
> > > > -------
> > > > Delete the WORKING <file>. If the WORKING <file> has been moved to
> > > > <moved> then delete <moved> too.
> > >
> > > No, let's not follow moves/copies for now. We can add that later.
>
> Ok, eases the task.
>
> New classification
> ===================
> Moves and copies are not handled. If a file is deleted but it has a copy
> or is moved no action is taken. We wait until wc-ng will provide true
> renames for us. I may have misunderstood how subversion will keep track
> of renames. I'm assuming it will be able to resolv both a local mv and
> an incoming mv. Have I understood things correctly?
>
> I've saying below that a lot of options is better fixed once we have
> wc-ng? Is this the right thinking? I guess many (most?) tree conflicts
> is about moves, like when refactoring in Java. I'm suggesting that we'd
> not handle moves until wc-ng.
>
> Could we have some generic APPLY-MY-MODS-ELSEWHERE option? For RENAME,
> ELSEWHERE, MOVE-MY-MODS we need user input to know where to do a merge.
> Aren't they much the same? Merging is hard, something that says 'merge
> this onto that' would probably help. I know that the resolver is
> supposed to be handled by users with a good grasp on subversion but it
> can still be tricky.
>
> If that was possible then stsp:s suggested OpenBSD sysmerge menu (it's
> in the beginning of this mail) could be displayed afterwards.
>
> Local add, incoming add
> -------------------------
> THEIRS: Put new BASE file in WORKING.
> MINE: Keep current WORKING file.
> RENAME-MINE:
> Move WORKING file to <user-suggest>. Replace WORKING file with
> the BASE-TARGET file.
> MERGE Merge BASE file1 onto WORKING file2.
>
> Local del, incoming del
> -------------------------
> THEIRS: Delete the file from WORKING and ACTUAL.
> MINE: Keep current WORKING file.
> RENAME: If renamed to two different names. Merge BASE-TARGET <moved>
> onto WORKING <moved>.
> ### We need the user to tell us the add-half of a rename until
> ### wc-ng is here. Until then <moved> must be a user suggestion.
>
> Local del, incoming edit
> -------------------------
> THEIRS: Replace the deleted WORKING file with edited BASE file.
> MINE: Keep current WORKING file.
> ELSEWHERE:
> ### wc-ng will automatically find a move. No need for this
> ### option?
>
> Locale edit, incoming del
> --------------------------
> THEIRS: Delete the file from WORKING and ACTUAL.
> MINE: Keep current WORKING file.
> MOVE-MY-MODS:
> ### wc-ng will automatically find a move. No need for this
> ### option?
>
> API changes
> ============
>
> We have
> --------
> 1) We already know which operations has caused the conflict. It's in
> svn_wc_operation_t. In case some cases will need to differ between sw/up
> and merge which I think will be the case.
>
> 2) We know which type of tree conflict svn_wc_conflict_reason_t,
> svn_wc_conflict_action_t
>
> 3) We have conflict choises already svn_wc_conflict_choise_t {
> svn_wc_conflict_choose_postpone
> svn_wc_conflict_choose_base, /* original version */
> svn_wc_conflict_choose_theirs_full, /* incoming version */
> svn_wc_conflict_choose_mine_full, /* own version */
> svn_wc_conflict_choose_theirs_conflict, /* incoming (for conflicted hunks)
> */
> svn_wc_conflict_choose_mine_conflict, /* own (for conflicted hunks) */
> svn_wc_conflict_choose_merged /* merged version */
> }
>
> 4) A code structure for invoking interactive commands, displaying diffs
> and choosing versions.
>
> We need
> --------
> 1) svn_cl__conflict_handler must use svn_wc_conflict_description2_t for
> some additional tree conflict info.
>
> 2) Handle the cases we can in svn_cl__conflict_handler, let the other fall
> through. (Or return svn_wc_conflict_choose_postpone). I'm thinking of
> letting all dir conflicts fall through as a first step.
>
> 3) Add some choises to svn_wc_conflict_choise_t.
> svn_wc_conflict_choose_{rename,elsewhere,my_moved_mods}?
>
> 4) Add calls to eb->conflict_resolver if check_tree_conflict() returns a
> conflict in:
> libsvn_wc/update_editor.c
> do_entry_deletion()
> add_directory()
> open_directory()
> add_file_with_history()
> open_file()
> Or are we supposed to call the conflict resolver after we have done the
> whole operation?
>
> 5) Create code to handle and execute the svn_wc_conflict_choise_t
> choises. in libsvn_wc/update_editor.c
>
> 6) Test to verify the interactive callback. Some detection tests needs
> to use the --non-interactive flag.
>
> -- Daniel
>
> [1] http://svn.haxx.se/dev/archive-2009-10/0816.shtml
>
