When the surface that owns a touch drag is destroyed mid-gesture, the compositor re-opens the touch grab by issuing a fresh `down` on the surface now under the finger (smithay pins touch focus at `down` and won't re-target on motion). That `down` arrives for a slot the main surface already holds as its primary, with the drag state already migrated here. Handling it through the normal `down` path would either restart the gesture or, since the slot is taken, demote it to an auxiliary touch — both abandon the in-flight drag.
`TouchHandler::down` now early-returns when the focused surface's `primary_touch_id` already equals the incoming slot, so the redundant `down` is a no-op and the following motion/up keep driving the migrated drag. Completes the cross-surface drag fix whose other half (migrating `primary_touch_id` on overlay teardown) already landed.
Pedro M. de Echanove Pasquin
48c5a89712