XCB: Don't core-dump if we can't connect to the X displayName

Exit with error, but don't crash.

Change-Id: Ie05c6480d8a44fda817ffffd14d9dfd8c951beef
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

1 files changed, 15 insertions, 2 deletions

diff --git a/src/plugins/platforms/xcb/qxcbintegration.cpp b/src/plugins/platforms/xcb/qxcbintegration.cpp
index b372ecd7c4..c9ecdceb0d 100644
--- a/src/plugins/platforms/xcb/qxcbintegration.cpp
+++ b/src/plugins/platforms/xcb/qxcbintegration.cpp
@@ -178,12 +178,25 @@ QXcbIntegration::QXcbIntegration(const QStringList &parameters, int &argc, char
 
     const int numParameters = parameters.size();
     m_connections.reserve(1 + numParameters / 2);
-    m_connections << new QXcbConnection(m_nativeInterface.data(), m_canGrab, m_defaultVisualId, displayName);
+    auto conn = new QXcbConnection(m_nativeInterface.data(), m_canGrab, m_defaultVisualId, displayName);
+    if (conn->isConnected())
+        m_connections << conn;
+    else
+        delete conn;
 
     for (int i = 0; i < numParameters - 1; i += 2) {
         qCDebug(lcQpaScreen) << "connecting to additional display: " << parameters.at(i) << parameters.at(i+1);
         QString display = parameters.at(i) + QLatin1Char(':') + parameters.at(i+1);
-        m_connections << new QXcbConnection(m_nativeInterface.data(), m_canGrab, m_defaultVisualId, display.toLatin1().constData());
+        conn = new QXcbConnection(m_nativeInterface.data(), m_canGrab, m_defaultVisualId, display.toLatin1().constData());
+        if (conn->isConnected())
+            m_connections << conn;
+        else
+            delete conn;
+    }
+
+    if (m_connections.isEmpty()) {
+        qCritical("Could not connect to any X display.");
+        exit(1);
     }
 
     m_fontDatabase.reset(new QGenericUnixFontDatabase());