From 1500d2283e17be72226b2960a79039254887977f Mon Sep 17 00:00:00 2001
From: Shawn Rutledge <shawn.rutledge@qt.io>
Date: Wed, 20 Feb 2019 13:55:03 +0100
Subject: Clear only one device from g_pointIdMap when all points released
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The new test tst_QTouchEvent::touchOnMultipleTouchscreens()
needs the touchpoint IDs to be predictable, but another test currently
has a QEXPECT_FAIL; without release events, g_pointIdMap continued to
hold the touchpoints that were there when the test failed.  So it's
necessary to add QWindowSystemInterfacePrivate::clearPointIdMap()
to be able to call it in the test cleanup function.

Fixes: QTBUG-73830
Change-Id: Ia6a70d028be95cd2b6676db6363ec408c0b116bc
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>
---
 src/gui/kernel/qwindowsysteminterface.cpp | 20 ++++++++++++++++++--
 src/gui/kernel/qwindowsysteminterface_p.h |  1 +
 2 files changed, 19 insertions(+), 2 deletions(-)

(limited to 'src/gui')

diff --git a/src/gui/kernel/qwindowsysteminterface.cpp b/src/gui/kernel/qwindowsysteminterface.cpp
index 5b32405f5e..7067ece1d8 100644
--- a/src/gui/kernel/qwindowsysteminterface.cpp
+++ b/src/gui/kernel/qwindowsysteminterface.cpp
@@ -695,13 +695,29 @@ QList<QTouchEvent::TouchPoint>
     }
 
     if (states == Qt::TouchPointReleased) {
-        g_nextPointId = 1;
-        g_pointIdMap->clear();
+        // All points on deviceId have been released.
+        // Remove all points associated with that device from g_pointIdMap.
+        // (On other devices, some touchpoints might still be pressed.
+        // But this function is only called with points from one device at a time.)
+        for (auto it = g_pointIdMap->begin(); it != g_pointIdMap->end();) {
+            if (it.key() >> 32 == quint64(deviceId))
+                it = g_pointIdMap->erase(it);
+            else
+                ++it;
+        }
+        if (g_pointIdMap->isEmpty())
+            g_nextPointId = 1;
     }
 
     return touchPoints;
 }
 
+void QWindowSystemInterfacePrivate::clearPointIdMap()
+{
+    g_pointIdMap->clear();
+    g_nextPointId = 1;
+}
+
 QList<QWindowSystemInterface::TouchPoint>
     QWindowSystemInterfacePrivate::toNativeTouchPoints(const QList<QTouchEvent::TouchPoint>& pointList,
                                                        const QWindow *window)
diff --git a/src/gui/kernel/qwindowsysteminterface_p.h b/src/gui/kernel/qwindowsysteminterface_p.h
index 9cb4e191cc..cea02fb8b7 100644
--- a/src/gui/kernel/qwindowsysteminterface_p.h
+++ b/src/gui/kernel/qwindowsysteminterface_p.h
@@ -537,6 +537,7 @@ public:
     static QList<QWindowSystemInterface::TouchPoint>
         toNativeTouchPoints(const QList<QTouchEvent::TouchPoint>& pointList,
                             const QWindow *window);
+    static void clearPointIdMap();
 
     static void installWindowSystemEventHandler(QWindowSystemEventHandler *handler);
     static void removeWindowSystemEventhandler(QWindowSystemEventHandler *handler);
-- 
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