A drag kept the frame's authored anchors: `GetPoint()` answered them afterwards, the frame kept following its old target, and a resize grip on a CENTER- or TOPLEFT-anchored frame moved the wrong edges.
In 1.12.1 every drag enters at `0x7652b0`, whose first act pins the frame (`0x768430`): `ClearAllPoints`, one TOPLEFT on the screen root's TOPLEFT at the current rect, and an explicit size. The pump `0x768710` moves that anchor (case 4) or, for each of the eight grips, computes the clamped size and re-pins shifted by the left and top travel only (`0x76898a`). A frame with no rect starts no drag (`0x7652cd`).
Drags now pin and pump that way, with one drag slot; `StartSizing` defaults to BOTTOMRIGHT (`0x776913`).
Tests: the pin and `GetPoint` after a drag, the eight grips on a CENTER-anchored frame, the clamps, the layout cache round trip, and stock chat-window resize and off-screen drop.
Fixes#173🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
