Bogus misalign reported when stair meets raftable water

Steps to recreate:

1. check Etc->Options->Toggles->Show Misaligns
2. Open the original 1stClassic.qst zelda 1 quest in the editor (download https://www.purezc.net/forums/index.php?showtopic=74096)
3. Navigate to map 1 screen 0x2F (47)
4. Observe a misalign shown at tile position 166. Similarly, this misalign is also visible on screen 0x3F (63) tile position 6

zmap::misaligned is returning true from the "case down" block with:

Code:

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        map == 0
        scr == 47
        i  == 166
        dir == 1

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