1 files changed, 12 insertions, 1 deletions
diff --git a/src/plugins/platforms/xcb/qxcbconnection.cpp b/src/plugins/platforms/xcb/qxcbconnection.cpp
index 7435e124dc..1fcee9cd89 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection.cpp
@@ -767,7 +767,10 @@ xcb_timestamp_t QXcbConnection::getTimestamp()
 
     xcb_generic_event_t *event = nullptr;
 
-    while (!event) {
+    // When disconnection is caused by X server, event will never be able to hold
+    // a valid pointer. isConnected(), which calls xcb_connection_has_error(),
+    // can handle this type of disconnection and properly quits the loop.
+    while (isConnected() && !event) {
         connection()->sync();
         event = eventQueue()->peek([window, dummyAtom](xcb_generic_event_t *event, int type) {
             if (type != XCB_PROPERTY_NOTIFY)
@@ -777,6 +780,14 @@ xcb_timestamp_t QXcbConnection::getTimestamp()
         });
     }
 
+    if (!event) {
+        // https://www.x.org/releases/X11R7.7/doc/xproto/x11protocol.html#glossary
+        // > One timestamp value (named CurrentTime) is never generated by the
+        // > server. This value is reserved for use in requests to represent the
+        // > current server time.
+        return XCB_CURRENT_TIME;
+    }
+
     xcb_property_notify_event_t *pn = reinterpret_cast<xcb_property_notify_event_t *>(event);
     xcb_timestamp_t timestamp = pn->time;
     free(event);