Region names lived in one first-wins name → id map that also served `GetName`, so a second region given a taken name answered `GetName()` with nil and was `<unnamed>` in its error strings.
In 1.12.1 the name lives on the region: `SetName` (`0x76c650`) keeps the region's own copy at `[+0x98]`, freed by its destructor (`0x76c560`) and read back by `GetName`. Only `_G` is first-come (`0x701bd0`, `0x701c8a`).
Each region now carries its name; `GetName` and the error strings read it directly, and the name map is a first-come lookup only, whose entry a free drops only when it holds that region.
Tests: same name twice, `$parentText` under colliding parents, the second region's error string, a free leaving a same-named sibling's name.
Fixes#939🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
