From ee4cf67371fb9b1047f50b6d40ac84fe19bf1b11 Mon Sep 17 00:00:00 2001
From: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Date: Fri, 31 May 2024 11:56:15 +0300
Subject: [PATCH] wayland: Refuse starting dnd if there's another dnd session
 in progress

If a new drag and drop session is started while there is already one
existing, it's possible to end up in a situation where the
SeatInterface::dragEnded signal is emitted the second time when one of
the data sources is destroyed.

CCBUG: 460374
---
 src/wayland/seat.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/wayland/seat.cpp b/src/wayland/seat.cpp
index 1b854d7993..6a15964bd3 100644
--- a/src/wayland/seat.cpp
+++ b/src/wayland/seat.cpp
@@ -1352,6 +1352,10 @@ void SeatInterface::setPrimarySelection(AbstractDataSource *selection)
 
 void SeatInterface::startDrag(AbstractDataSource *dragSource, SurfaceInterface *originSurface, int dragSerial, DragAndDropIcon *dragIcon)
 {
+    if (d->drag.mode != SeatInterfacePrivate::Drag::Mode::None) {
+        return;
+    }
+
     if (hasImplicitPointerGrab(dragSerial)) {
         d->drag.mode = SeatInterfacePrivate::Drag::Mode::Pointer;
         d->drag.transformation = d->globalPointer.focus.transformation;