Prompted by the discussion in the users group , I've been investigating why the prompt to merge doesn't appear sometimes.
When merging with a specified range, CSVNProgressDlg::CmdMerge() is used while merging without a range (or All revisions) is using CSVNProgressDlg::CmdMergeAll().
CSVNProgressDlg::CheckUpdateAndRetry() should check if an update is required:
if (GetSVNError() && GetSVNError()->apr_err == SVN_ERR_CLIENT_MERGE_UPDATE_REQUIRED)
... prompt the user to update or cancel ...
In CmdMerge, the call to GenerateMergeLogMessage() (line 3384) seems to reset the latest error (SVNBase::m_err) so GetSVNError() will return false.
A naive fix would be to condition the call to GenerateMergeLogMessage() with if (!bFailed), however that is a direct revert of r27728 "Generate the merge log message even if the merge returned with an error: a merge conflict also returns an error.".
I'm instead considering to check GetSVNError() and the actual error message but I don't have enough knowledge about the different error messages that could appear.
Ideally, I'd like to do check for a list of error messages that indicate a merge failure and create a log message in these cases (it seems unneccesary to create a log message in case of a network failure). Unfortunately I don't know how to figure out this list of error messages.
Another option would be to check for only SVN_ERR_CLIENT_MERGE_UPDATE_REQUIRED. That would solve the current bug but could open up for other bugs in the future if/when we want to look for other error messages later in the code.
Any opinion on this?
On a side note, CmdMergeReintegrate() (and CmdMergeReintegrateOldStyle() and CmdMergeReintegrateOldStyle()) should probably also be changed to run GenerateMergeLogMessage() in case of a merge conflict to give similar behaviour in all kind of merges.