I split a 10 minute movie at 18 locations, but didn't remove any of the segments between any splits before saving it.  

Coming back to the project later, I decided that 7 of those splits were unnecessary, so before removing any segments from the movie, I wanted to re-join or heal the splits I no longer required.  

However I could not find any way to unsplit an existing split, even though nothing had yet been removed between any splits.

I realise that the unused split points make no difference to how the movie plays, but the timeline now appears unnecessarily messy.

More seriously, when I come back to the project at a later time, after removing the genuinely unwanted segments, the dummy splits will make it more difficult to see where stuff has actually been removed.