Merge is out of date?

So, I encountered a weird problem earlier tonight while trying to merge changes from our trunk back into a branch I’ve been working on. The merge went successfully and I could see all the changes locally. However, when I attempted to check in the changes, I got the following error message:

svn: File 'path/to/file' is out of date

This wasn’t terribly unusual, with the exception of the case I just checked out the branch from the repository. When I performed an update, nothing was updated which further complicated the situation. When I used the --force switch, only then did one of my folders update and indicate that it was in a conflicted state. When I resolved the conflict and attempted to check back in, guess what? The same error message.

This is when I started Googling to see if I could find someone else who had this problem, but alas found no answers. I then started trying to compare the differences between the versions, including what was available in the most recent trunk release and found something interesting. The most recent trunk didn’t have any properties named svn:mergeinfo. This was despite multiple merges already taking place in the past. Yet, when I looked at the merge that I am attempting to perform, the following mergeinfo appeared:

/branches/timelog-and-multi-speaker-ui:430-526
/trunk:532-533

I had specified only to merge versions 532-533 - nothing before then. Thus, the previous merge version was extremely unusual, and likely was what was causing the conflicts upon checkin. Sure enough, when I deleted that line in the svn:mergeinfo property, I was able to checkin successfully.

So, the lesson to be learned is if you try to merge and find you’re blocked because something isn’t really out-of-date, check your mergeinfo.