I think I am having this same issue. Makes playing the game in this snapshot near impossible. Every time you interact with any interface block (chest, crafting table, etc.) the action key becomes “stuck” on and you can’t really get out of it. Escaping just reopens it, and if you manage to get the focus to move in the split second before that happens (which is hard) it’s like the key is stuck on as it starts placing tons of torches (in my off hand) on every block I face until I close or minimize the game and come back into it.
Another long time user (since alpha) on a MacBook Pro that is greatly affected by this change. I waited until the release of the update to try it, and now can't really play comfortably at all. If I could simply map ctr+click to be right click most of the problems would be fixed, but you can't seem to map modifier+key, only single keys.
I do agree with several others who said that ctr+click should just automatically be interpreted as a right click the way lwjgl used to do it. If the lwjgl people changed this for some reason and won't change it back, Mojang should just do it on their end instead.
I couldn’t move the cursor fast enough while rapidly hitting the escape key to show how I could stop it from instantly re-opening while holding my phone to record it (which is hard enough to make happen even when trying to do it with two free hands). But as I said above, doing that would cause me to rapidly place blocks or flip the door open and close over and over again without hitting any keys (as if the action key was being held down).