Document one more bug.

docs/bugs_and_glitches.md

@@ -598,7 +598,7 @@ This is a bug with `LoadEnemyMon.CheckMagikarpArea` in [battle/core.asm](battle/
 
 This is a bug with `StartTrainerBattle_DetermineWhichAnimation` in [engine/battle_start.asm](engine/battle_start.asm):
 
-```
+```asm
 StartTrainerBattle_DetermineWhichAnimation: ; 8c365 (23:4365)
 ; The screen flashes a different number of times depending on the level of
 ; your lead Pokemon relative to the opponent's.
@@ -683,6 +683,32 @@ This is a bug with `DoPlayerMovement.CheckWarp` in [engine/player_movement.asm](
 ```
 
 
+## `LoadMetatiles` wrap around past 128 blocks
+
+[home/map.asm](home/map.asm):
+
+```asm
+	; Set hl to the address of the current metatile data ([TilesetBlocksAddress] + (a) tiles).
+	; This is buggy; it wraps around past 128 blocks.
+	; To fix, uncomment the line below.
+	add a ; Comment or delete this line to fix the above bug.
+	ld l, a
+	ld h, 0
+	; add hl, hl
+	add hl, hl
+	add hl, hl
+	add hl, hl
+	ld a, [TilesetBlocksAddress]
+	add l
+	ld l, a
+	ld a, [TilesetBlocksAddress + 1]
+	adc h
+	ld h, a
+```
+
+**Fix:** Delete `add a` and uncomment `add hl, hl`.
+
+
 ## Surfing directly across a map connection does not load the new map
 
 ([Video](https://www.youtube.com/watch?v=XFOWvMNG-zw))

home/map.asm

@@ -152,9 +152,12 @@ LoadMetatiles:: ; 2198
 	ld e, l
 	ld d, h
 	; Set hl to the address of the current metatile data ([TilesetBlocksAddress] + (a) tiles).
-	add a
+	; This is buggy; it wraps around past 128 blocks.
+	; To fix, uncomment the line below.
+	add a ; Comment or delete this line to fix the above bug.
 	ld l, a
 	ld h, 0
+	; add hl, hl
 	add hl, hl
 	add hl, hl
 	add hl, hl