Review follow-up (#3785, CodeRabbit): commands in SELECTS_GIVEN_IDS run select.set with the given ids before their body; when the body then returned an ordinary error, the ids stayed selected (and their layer current), while a panic restored the selection and refused ids never changed it. The dispatcher now keeps the active document's selection and current layer from before select.set and restores them when the body errors. This affects every command in SELECTS_GIVEN_IDS (Duplicate, Arrange, Clipping Mask, Compound Path, Group/Ungroup, Hide, Lock, Move, the Pathfinder panel commands including Trap, and the transforms). Tests: Trap with ids whose edges don't meet, and Intersect with ids of shapes that don't overlap, leave the selection as it was.
The Pathfinder panel menu's Trap… (object.pathfinder.trap) and Effect › Pathfinder › Trap… (pathfinder.trap, live on groups) share one geometry (vectorcraft_pathops::trap_band, vectorcraft_effects::trap): Thickness, Height/Width, Tint Reduction, Traps with Process Color and Reverse Traps, plus the effect's Precision and Remove Redundant Points. The panel's Trap is one undo step and groups the traps above the topmost selected object. Behaviour from https://helpx.adobe.com/illustrator/using/trapping.html and https://helpx.adobe.com/illustrator/using/pathfinder-panel-overview.html.
Taha-Mahmoodi