Several times in different worlds, I've found new villages with villagers running around. I know villagers aren't returning to their houses at night, so I'm used to seeing the blacksmith running around when I get to a village, but I've found plain old farmers running around, too. I know villagers can't open doors on their own. Because they just wander off, I don't open their doors for them unless I've walled-off the whole village. Today, I found 3 villagers wandering around - the blacksmith and two farmers - and found 2 farmer houses without doors.

What I expected to happen was:
Villagers would only spawn in houses with doors... and would stay safe in those houses until I opened the door or until a later update gave them the AI to open doors.

What actually happened was:
Villagers are running loose and there are villager houses without doors.

Steps to Reproduce:
1. Find a village with farmers running around.
2. Check houses for doors.
3. Find farmers' houses without doors.
4. Watch helplessly as the blacksmith and farmers wander into caves and dark forests.

Included screenshots:
1. Farmer and blacksmith hanging out at the edge of the village at dawn. They'd been partying on the hill all night.
2. Farmer house with no door.
3. Farmer who was running around the village when I got there.

I'm playing SSP, but staying in peaceful mode until I can round up the villagers, wall them in, and build an iron golem to keep them safe.