TFMurphy
Level: Smitemaster
Rank Points: 3118
Registered: 06-11-2007
IP: Logged

File: Bridge Bug.hold (950 bytes)
Downloaded 46 times.
License: Public Domain

Rather nasty bug here that causes DROD to crash with no accompanying assertion errors.

The crash appears to occur mainly when a builder places a bridge tile that connects two "monitored" bridges (i.e. two bridges that could drop if all trapdoors they're connected to are removed). I'm not sure of all the conditions to cause the crash - there's a few unique formations that can cause DROD to keep running, but things start seeming a little unstable with further bridge building afterwards. (As an example, one tile built to connect two bridges might cause DROD to accept it, but a tile placed next to it might cause it to crash.)

I've attached a Hold that demonstrates the behavior fairly easily. You can simply wait for the crash to happen, or influence in several ways: one example is to immediately turn your sword southwest to allow the Red Citizen to build its first bridge at (21,15), which will cause the crash to occur when the White Citizen makes the first connection (rather than the crash happening on the second connection). Another example is to run forward and drop the center bridge: the crash will then occur when a tile *next* to the one that connects the two upper bridges is placed.

I'm not entirely sure what's the cause of the bug here - probably to do with index removal problems or similar. I have also tested this in Build 84, and it's still buggy there. So I hope this is enough to successfully find and fix it.

mrimer
Level: Legendary Smitemaster

Rank Points: 5198
Registered: 02-04-2003
IP: Logged

Thanks! I fixed the crash. It was an index inconsistency issue. This is fixed in build 85, and also will be in RPG build 56.

____________________________
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Gandalf the Grey. That was my name.
I am Gandalf the White.
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