TortoiseHG: undoing commit that fails

I've been using TortoiseHG for some time now and I've been running into the same issue once in a while.

Sometimes, when I commit my work, it gives me an error, saying that one (or more) of my files is being used开发者_开发百科 by another process. However, the commit still goes through and is visible in the repository browser.

Next, after closing the processes that caused the error, I reopen the commit dialog that says that there are still changes to be committed (meaning the first commit didn't really do anything). I do another commit, which accomplishes what I wanted to do in the first place, but now I have a different problem: the repository now has two heads. Of course, I'm forced to merge the two heads after this, but my process seems unclean.

Is there a better way to get around such a problem, such as by somehow undoing the commit (but not reverting my files), or should I not bother cleaning stuff like this up?

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hg rollback at the command line should revert the commit but not the changes (I don't use tortoisehg, so unclear if it puts that in a nice UI).