File xcb-fix-yet-another-crash-when-screens-are-disconnected.patch of Package libqt5-qtbase.2170

From d72da0b4b2ee089156d1bd614523838b1635bbf5 Mon Sep 17 00:00:00 2001
From: Shawn Rutledge <shawn.rutledge@theqtcompany.com>
Date: Fri, 4 Sep 2015 13:27:48 +0200
Subject: [PATCH] xcb: fix yet another crash when screens are disconnected

Can't assume that m_screens is not an empty list.

Task-number: QTBUG-42985
Change-Id: I6f9422638c219123dc898813910d03c7afbd1450
Reviewed-by: Uli Schlachter <psychon@znc.in>
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>
---
 src/plugins/platforms/xcb/qxcbconnection.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/plugins/platforms/xcb/qxcbconnection.cpp b/src/plugins/platforms/xcb/qxcbconnection.cpp
index f65437f..c35b019 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection.cpp
@@ -1300,10 +1300,12 @@ void QXcbConnection::sendConnectionEvent(QXcbAtom::Atom a, uint id)
     memset(&event, 0, sizeof(event));
 
     const xcb_window_t eventListener = xcb_generate_id(m_connection);
+    xcb_screen_iterator_t it = xcb_setup_roots_iterator(m_setup);
+    xcb_screen_t *screen = it.data;
     Q_XCB_CALL(xcb_create_window(m_connection, XCB_COPY_FROM_PARENT,
-                                 eventListener, m_screens.at(0)->root(),
+                                 eventListener, screen->root,
                                  0, 0, 1, 1, 0, XCB_WINDOW_CLASS_INPUT_ONLY,
-                                 m_screens.at(0)->screen()->root_visual, 0, 0));
+                                 screen->root_visual, 0, 0));
 
     event.response_type = XCB_CLIENT_MESSAGE;
     event.format = 32;
-- 
2.3.5