3 files changed, 40 insertions, 1 deletions
diff --git a/src/plugins/platforms/cocoa/qcocoainputcontext.mm b/src/plugins/platforms/cocoa/qcocoainputcontext.mm
index 9e3d747cd7..9221099a57 100644
--- a/src/plugins/platforms/cocoa/qcocoainputcontext.mm
+++ b/src/plugins/platforms/cocoa/qcocoainputcontext.mm
@@ -124,7 +124,22 @@ void QCocoaInputContext::connectSignals()
 void QCocoaInputContext::focusObjectChanged(QObject *focusObject)
 {
     Q_UNUSED(focusObject);
-    mWindow = QGuiApplication::focusWindow();
+    if (mWindow == QGuiApplication::focusWindow()) {
+        if (!mWindow)
+            return;
+
+        QCocoaWindow *window = static_cast<QCocoaWindow *>(mWindow->handle());
+        QNSView *view = qnsview_cast(window->view());
+        if (!view)
+            return;
+
+        if (NSTextInputContext *ctxt = [NSTextInputContext currentInputContext]) {
+            [ctxt discardMarkedText];
+            [view cancelComposingText];
+        }
+    } else {
+        mWindow = QGuiApplication::focusWindow();
+    }
 }
 
 void QCocoaInputContext::updateLocale()
diff --git a/src/plugins/platforms/cocoa/qnsview.h b/src/plugins/platforms/cocoa/qnsview.h
index c37c45ce80..384f14ba3a 100644
--- a/src/plugins/platforms/cocoa/qnsview.h
+++ b/src/plugins/platforms/cocoa/qnsview.h
@@ -70,6 +70,7 @@ Q_FORWARD_DECLARE_OBJC_CLASS(QT_MANGLE_NAMESPACE(QNSViewMouseMoveHelper));
     Qt::MouseButtons m_acceptedMouseDowns;
     Qt::MouseButtons m_frameStrutButtons;
     QString m_composingText;
+    QPointer<QObject> m_composingFocusObject;
     bool m_sendKeyEvent;
     QStringList *currentCustomDragTypes;
     bool m_sendUpAsRightButton;
@@ -104,6 +105,7 @@ Q_FORWARD_DECLARE_OBJC_CLASS(QT_MANGLE_NAMESPACE(QNSViewMouseMoveHelper));
 - (void)viewDidHide;
 - (void)viewDidUnhide;
 - (void)removeFromSuperview;
+- (void)cancelComposingText;
 
 - (BOOL)isFlipped;
 - (BOOL)acceptsFirstResponder;
diff --git a/src/plugins/platforms/cocoa/qnsview.mm b/src/plugins/platforms/cocoa/qnsview.mm
index a40bdfd314..ba5c0ea25d 100644
--- a/src/plugins/platforms/cocoa/qnsview.mm
+++ b/src/plugins/platforms/cocoa/qnsview.mm
@@ -1712,6 +1712,7 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
     }
 
     m_composingText.clear();
+    m_composingFocusObject = nullptr;
 }
 
 - (void) setMarkedText:(id)aString selectedRange:(NSRange)selectedRange replacementRange:(NSRange)replacementRange
@@ -1766,6 +1767,7 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
     m_composingText = preeditString;
 
     if (QObject *fo = m_platformWindow->window()->focusObject()) {
+        m_composingFocusObject = fo;
         QInputMethodQueryEvent queryEvent(Qt::ImEnabled);
         if (QCoreApplication::sendEvent(fo, &queryEvent)) {
             if (queryEvent.value(Qt::ImEnabled).toBool()) {
@@ -1778,6 +1780,25 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
     }
 }
 
+- (void)cancelComposingText
+{
+    if (m_composingText.isEmpty())
+        return;
+
+    if (m_composingFocusObject) {
+        QInputMethodQueryEvent queryEvent(Qt::ImEnabled);
+        if (QCoreApplication::sendEvent(m_composingFocusObject, &queryEvent)) {
+            if (queryEvent.value(Qt::ImEnabled).toBool()) {
+                QInputMethodEvent e;
+                QCoreApplication::sendEvent(m_composingFocusObject, &e);
+            }
+        }
+    }
+
+    m_composingText.clear();
+    m_composingFocusObject = nullptr;
+}
+
 - (void) unmarkText
 {
     if (!m_composingText.isEmpty()) {
@@ -1793,6 +1814,7 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
         }
     }
     m_composingText.clear();
+    m_composingFocusObject = nullptr;
 }
 
 - (BOOL) hasMarkedText