While following a human subject resolve a merge conflict, I noticed the subject was happy after solving all conflicts and expected everything to be fine.
The repository browser shows the status of the repository as "Merged - master" so it really appears to be fine. The blue files in the tree didn't ring a bell so the subject continued to work (more on that in another bug).
After solving all conflicts, the user should be prompted if he wants to commit the resolution and if not, tell him/her what it implies.
In a bit sarcastic manner, here's my take on it:
"Congratulations for resolving all conflicts! Would you like to now commit your resolution or keep reviewing your changes?
After you are done, you must commit all changes before continuing.
[ Commit... ] [ No, thanks ]"
This would greatly help the flow and make the user aware all is not well yet. Hitting "Commit..." will bring the commit dialog as you would normally when you want to commit all changes.
Even for a long time git user like me, this would remind me that no automatic commit was done.