Drag and Drop: Pressing Escape while carrying a payload automatically cancel the active drag and drop. (#9071)

docs/CHANGELOG.txt

@@ -122,6 +122,8 @@ Other Changes:
 - Drag and Drop:
   - Added ImGuiDragDropFlags_AcceptDrawAsHovered to make accepting item render
     as hovered, which can allow using e.g. Button() as drop target. (#8632)
+  - Pressing Escape while carrying a payload automatically cancel the
+    active drag and drop. (#9071)
   - Style: added ImGuiCol_DragDropTargetBg, style.DragDropTargetRounding,
     style.DragDropTargetBorderSize and style.DragDropTargetPadding to configure
     the drop target highlight. (#9056) [@aaronkirkham]

imgui.cpp

@@ -5534,6 +5534,11 @@ void ImGui::NewFrame()
     g.DragDropWithinSource = false;
     g.DragDropWithinTarget = false;
     g.DragDropHoldJustPressedId = 0;
+    if (g.DragDropActive && IsKeyPressed(ImGuiKey_Escape, ImGuiInputFlags_None, g.ActiveId)) // Also works when g.ActiveId==0 (aka leftover payload in progress, no active id)
+    {
+        ClearActiveID();
+        ClearDragDrop();
+    }
     g.TooltipPreviousWindow = NULL;
 
     // Close popups on focus lost (currently wip/opt-in)