[PATCH] Update and switch APIs call conflict resolver at end of operation

Following on from the fix for issue #4316 "Merge errors out after resolving conflicts" r1459012, in which I made the merge APIs call the conflict resolver callback for all conflicts before returning, I mentioned that we should do the same for update and switch [1].  I'll explain a bit more. Currently, subversion/svn/update-cmd.c:svn_cl__update() does this:   * Call svn_client_update4(...)     - with ctx->conflict_func2 set to svn_cl__conflict_func_postpone()       which records the conflicted paths but does not resolve them.   * Call svn_cl__resolve_postponed_conflicts()     - which calls svn_client_resolve()     - with ctx->conflict_func2 set to svn_cl__conflict_func_interactive()       which does interactive or non-interactive (pre-specified) resolution. There's something wrong with this usage pattern.  svn_client_update4() claims to support a conflict resolver callback, and yet 'svn' -- a really simple client application -- doesn't like the way it works, and instead uses the callback just to collect a list of paths and then runs its own conflict resolution loop instead.  Why? AFAIK, the two main reasons are:   - If the client is going to do interactive resolution, that could take a long time, and so the client prefers to wait until all of the repository-contacting phase of the update is complete, to avoid network timeouts.   - When resolving a tree conflict, we can be sure that all the incoming changes have been received, so that if we need to look at more than one path (such as for a tree conflict involving a copy or a move) then we know that the changes have been received for any path we need to look at. Other reasons are consistency (by making update and switch work the same as merge, we can get rid of some support code in 'svn') and making this logic available to all clients (even if GUI clients, for example, may not use this). I now intend to make libsvn_client do the resolving (I mean call the resolver callback) at the end of the update, for each conflicted path.  And 'switch', of course.  I see this as a development of the idea that resulted in 'svn' doing the two-stage think it is presently doing. With this patch, subversion/svn/update-cmd.c:svn_cl__update() will do this:   * Call svn_client_update4(...)     - with ctx->conflict_func2 set to svn_cl__conflict_func_interactive()       which does interactive or non-interactive (pre-specified) resolution.     - which calls the callback after completing the update, before returning. This changes the notifications a bit, as mentioned in the log message (which is in the patch file). I will commit this soon if no objections. - Julian [1] At the end of the dev@ message "Re: [PATCH] Fix issue #4316 - Merge errors out after resolving conflicts" by Julian Foad on 2013-03-20, <http://svn.haxx.se/dev/archive-2013-03/0340.shtml>. -- Certified & Supported Apache Subversion Downloads: http://www.wandisco.com/subversion/download