pokeemerald/docs/bugs_and_glitches.md

Bugs and Glitches

These are known bugs and glitches in the original Pokémon Emerald game: code that clearly does not work as intended, or that only works in limited circumstances but has the possibility to fail or crash. Defining the BUGFIX and UBFIX preprocessor variables will fix some of these automatically. UBFIX will already be defined for MODERN builds.

Fixes are written in the diff format. If you've used Git before, this should look familiar:

 this is some code
-delete red - lines
+add green + lines

Contents

• Scrolling through items in the bag causes the image to flicker

Scrolling through items in the bag causes the image to flicker

Fix: Add the following function to src/item_menu_icons.c:

+void HideBagItemIconSprite(u8 id)
+{
+	u8 *spriteId = &gBagMenu->spriteId[10];
+	if (spriteId[id] != 0xFF)
+	{
+		gSprites[spriteId[id]].invisible = TRUE;
+	}
+}

and its corresponding declaration in include/item_menu_icons.h:

+void HideBagItemIconSprite(u8 id);

Then edit BagMenu_MoveCursorCallback in src/item_menu.c:

	...
{
-	RemoveBagItemIconSprite(1 ^ gBagMenu->itemIconSlot);
+	HideBagItemIconSprite(gBagMenu->itemIconSlot ^ 1);
+	RemoveBagItemIconSprite(gBagMenu->itemIconSlot);
	if (itemIndex != LIST_CANCEL)
	...