GameTooltip setters accepted links, slots and indices that 1.12.1 refuses, and showed what it would not. Each one now checks and answers as its handler does.
- SetHyperlink takes only `item:` or `enchant:` (case-folded, `0x5320b1`), checks for an already-held link before the id, and raises `Unknown link type` on anything else.
- SetAction clears first. An Attack slot shows one white ATTACK line (`0x5323ad`).
- The trade skill, craft and trainer setters raise their lines on a bad index; a craft header clears and hides.
- Merchant and trade subtract 1.0 before truncating (`0x534159`).
- Any region can own the tooltip. A Font owner raises, written as a `Deviation:` (the client's `0x5313c9` is undefined there).
- Every setter checks `this` before its index.
Each fix has a test that fails without it.
Fixes#2544Fixes#2545Fixes#2546Fixes#2547Fixes#2548Fixes#2549🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Sam Sung
6db07056ed