QNX: Fix input lag

We were breaking out of select() too early with a timeout of -1.

This is a backport of
qtbase commit ba8f3002d49d9941b2991fbe4d78883ea59827b2

Change-Id: I65e534caea665fea3d99de621bcdbcf7c47fac55
Reviewed-by: Kevin Krammer <kevin.krammer@kdab.com>
Reviewed-by: Thomas McGuire <thomas.mcguire@kdab.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/corelib/kernel/qeventdispatcher_blackberry.cpp b/src/corelib/kernel/qeventdispatcher_blackberry.cpp
index 483171b..5711903 100644
--- a/src/corelib/kernel/qeventdispatcher_blackberry.cpp
+++ b/src/corelib/kernel/qeventdispatcher_blackberry.cpp
@@ -246,6 +246,14 @@ void QEventDispatcherBlackberry::unregisterSocketNotifier(QSocketNotifier *notif
 
 static inline bool updateTimeout(int *timeout, const struct timeval &start)
 {
+    // A timeout of -1 means we should block indefinitely. If we get here, we got woken up by a
+    // non-IO BPS event, and that event has been processed already. This means we can go back and
+    // block in bps_get_event().
+    // Note that processing the BPS event might have triggered a wakeup, in that case we get a
+    // IO event in the next bps_get_event() right away.
+    if (*timeout == -1)
+        return true;
+
     if (Q_UNLIKELY(!QElapsedTimer::isMonotonic())) {
         // we cannot recalculate the timeout without a monotonic clock as the time may have changed
         return false;