From 22d612ef14416881fb2edf54e950e57fe5e6a115 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=9F=B3=E5=8D=9A=E6=96=87?= <sbw@sbw.so>
Date: Fri, 12 Jan 2018 15:25:28 +0800
Subject: [PATCH] fix crash when drag out of preview container.

because the tracking window is unavilable.

Change-Id: I6cbdf76c7eb3eebcb628aa13496c06c4a7d4b692
---
 frame/item/components/previewcontainer.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/frame/item/components/previewcontainer.cpp b/frame/item/components/previewcontainer.cpp
index 2d719e3b0..4065bfaa3 100644
--- a/frame/item/components/previewcontainer.cpp
+++ b/frame/item/components/previewcontainer.cpp
@@ -188,6 +188,9 @@ void PreviewContainer::leaveEvent(QEvent *e)
 
 void PreviewContainer::dragEnterEvent(QDragEnterEvent *e)
 {
+    if (!m_wmHelper->hasComposite())
+        return;
+
     e->accept();
 
     m_needActivate = false;