FixRematch

**Temporary compatibility shim that fixes the Rematch 5.3.1 blank-window bug in patch 12.1.**

### The problem

Patch 12.1.0 removed the global `MouseIsOver()` function from Blizzard's UI code, with no transition shim in `Deprecated_12_1_0.lua`. Rematch 5.3.1 (the latest release as of this writing) still calls it in 14 places across 7 files. One of those calls sits in the loadout panel's `Update()` and runs on every window refresh, so the resulting Lua error aborts Rematch's whole rendering chain — the window opens but stays completely blank. The same removal also breaks Rematch's minimized view, right-click menus, drag-and-drop, the leveling queue and the notes card, as well as BtWQuests' map pin mouse-over handlers.

If you run an error-suppressing addon (or have script errors turned off), all of this fails silently — you just get an empty window.

### The fix

This addon restores `MouseIsOver` exactly as Blizzard implemented it up to 12.0.7 (`Blizzard_UIParent/Shared/UIParent.lua`) — a one-line pass-through to the modern `region:IsMouseOver()` method:

```lua

if not MouseIsOver then

    function MouseIsOver(region, topOffset, bottomOffset, leftOffset, rightOffset)

        return region:IsMouseOver(topOffset, bottomOffset, leftOffset, rightOffset)

    end

end

```

That is the entire addon. No settings, no slash commands, no hooks, no saved variables, no measurable overhead.

### When to uninstall

The `if not MouseIsOver` guard means the shim deactivates by itself if Blizzard ever restores the function. Once Rematch ships an official 12.1-compatible update, this addon becomes unnecessary and you can safely delete it (leaving it installed is harmless).

### Notes

- Not affiliated with Rematch or its author Gello — Rematch remains entirely his work. This shim only bridges the gap until an official update, and contains zero Rematch code.

- Patch 12.1 also introduced "secret value" restrictions that can prevent Rematch from identifying some pet-battle targets (shown as "Unknown (npc ID …)"). That is a separate issue this shim does not and cannot address.