When Link is standing directly to the right or left of a water combo, he will move a full tile instead of a half tile. This is especially an issue when a doorway on the top or bottum of a room is bordered by water tiles:
WFFW
W = Water
F = Floor
Link will not line up with the doorway because he is constantly walking a full tile instead of half a tile. This bug only occurs if there is a water tile to the left or right of Link: the bug does not occur if the water combos are only above or below Link. Also, Link is fine if he is positioned halfway across a tile horizontally.
One final note: this bug also seems to happen when Link is swimming. When he first enters water and moves, he suddenly stops swimming and walks a full tile before resuming swimming.
So, wait, no diagonal movement, I suppose?
No Z3 movement enabled. I can produce this bug on both a 2.10 quest and a quest I update every new build.
For example:
LWWWL
L = Land
W = Water
If Link moves while on either land combo, he will walk a full tile. As for the bug while in water:
If Link moves when swimming in the first or third water combo, he will move a full tile. However, he will play his walking animation when he does so, so it appears that he "walks" on water.
As mentioned before, Link will only move a full tile if he is directly next to the land-water border. If he is aligned horizontally half-way on a tile, he will move normally.
When searching for this bug, look into my other recently reported ladder-combo bug. Both bugs seem to have similar circumstances, and may even be the result of the same bug in the code.
Edit: Bug does not occur when Z3 movement is enabled. Only occurs when Z3 movement is disabled.
Bug is still present in 660, and I have an update. It seems that Link is being snapped to the 16x16 grid when he is to the left or right of a walkable-water border. Whenever he moves, he moves to the next spot on the grid (usually a full tile movement) and plays his walking animation while doing so. Thus, he will appear to "walk on water" when swimming next to the walkable combos. Another new twist to this bug is that Link's diving animation (and possibly the entire dive itself) lasts for only a frame or two when next to a walkable combo. Once again, this is only when Z3 movement is disabled.
http://rapidshare.com/files/69775490/BugTest1.qst.html
Here is a test quest made in 660 from the default template. It shows 3 bugs. The water bug is demonstrated in the first few rooms of the dungeon.
Based on this quest, the following is true and can be confirmed about this bug:
Only happens when Z3 movement is not enabled.
Bug does not occur if Link does not have the flippers.
When Link has the flippers, he will snap to the 16x16 grid when he moves when to the left or right of a border between an unwalkable water combo and a walkable combo.
The water must be unwalkable.
Link performs the walk animation when he moves in this manner, even when in the water.
Link cannot perform a full-length dive when next on a tile that meet's the bug's requirements. The dive animation will be cut short if he dives on an adjacent tile and then moves into a 'buggy' tile.
Try to enter the top door in the room above the dungeon enterance after getting the flippers: shows the real issue the bug poses.
Fixed in the next build, I think.
The Link walkability detection code is a horrible mess, and very subtle.
Bug is confirmed dead in build 668. This was a subtle one because it happened only when Z3 movement was disabled. Many testers might be trying quests with Z3 movement on. I'll continue testing without Z3 movement, in case any other bugs that occur when Z3 movement is disabled appear.