Document bugfix: ScriptCall can overflow wScriptStack and crash

docs/bugs_and_glitches.md

@@ -1422,43 +1422,46 @@ This supports up to six entries.
 
 ## `ScriptCall` can overflow `wScriptStack` and crash
 
-In [engine/overworld/scripting.asm](/engine/overworld/scripting.asm):
+**Fix:** Edit `ScriptCall` in [engine/overworld/scripting.asm](/engine/overworld/scripting.asm):
 
-```asm
+```diff
-ScriptCall:
+ ScriptCall:
-; Bug: The script stack has a capacity of 5 scripts, yet there is
+-; Bug: The script stack has a capacity of 5 scripts, yet there is
-; nothing to stop you from pushing a sixth script.  The high part
+-; nothing to stop you from pushing a sixth script.  The high part
-; of the script address can then be overwritten by modifications
+-; of the script address can then be overwritten by modifications
-; to wScriptDelay, causing the script to return to the rst/interrupt
+-; to wScriptDelay, causing the script to return to the rst/interrupt
-; space.
+-; space.
-
+-
-	push de
++	ld hl, wScriptStackSize
-	ld hl, wScriptStackSize
++	ld a, [hl]
-	ld e, [hl]
++	cp 5
-	inc [hl]
++	ret nc
-	ld d, $0
+ 	push de
-	ld hl, wScriptStack
+-	ld hl, wScriptStackSize
-	add hl, de
+-	ld e, [hl]
-	add hl, de
+ 	inc [hl]
-	add hl, de
++	ld e, a
-	pop de
+ 	ld d, 0
-	ld a, [wScriptBank]
+ 	ld hl, wScriptStack
-	ld [hli], a
+ 	add hl, de
-	ld a, [wScriptPos]
+ 	add hl, de
-	ld [hli], a
+ 	add hl, de
-	ld a, [wScriptPos + 1]
+ 	pop de
-	ld [hl], a
+ 	ld a, [wScriptBank]
-	ld a, b
+ 	ld [hli], a
-	ld [wScriptBank], a
+ 	ld a, [wScriptPos]
-	ld a, e
+ 	ld [hli], a
-	ld [wScriptPos], a
+ 	ld a, [wScriptPos + 1]
-	ld a, d
+ 	ld [hl], a
-	ld [wScriptPos + 1], a
+ 	ld a, b
-	ret
+ 	ld [wScriptBank], a
+ 	ld a, e
+ 	ld [wScriptPos], a
+ 	ld a, d
+ 	ld [wScriptPos + 1], a
+ 	ret
 ```
 
-*To do:* Fix this bug.
-
 
 ## `LoadSpriteGFX` does not limit the capacity of `UsedSprites`
 

engine/overworld/scripting.asm

@@ -1454,7 +1454,7 @@ ScriptCall:
 	ld hl, wScriptStackSize
 	ld e, [hl]
 	inc [hl]
-	ld d, $0
+	ld d, 0
 	ld hl, wScriptStack
 	add hl, de
 	add hl, de