Changed call sequence of seeking in Phonon MMF backend, for streaming

Modified the sequence of calls made to the MMF APIs when seeking
during ongoing playback.  This fixes a bug found during early testing
of streaming playback, whereby playback would not resume following
the seeking operation.  This was due to an interaction between the
pause / seek / play operations, and the buffering callbacks received
from the MMF, which caused the backend to enter an incorrect state.

Task-number: QTBUG-4660
Reviewed-by: Frans Englich

2 files changed, 11 insertions, 19 deletions

diff --git a/src/3rdparty/phonon/mmf/abstractmediaplayer.cpp b/src/3rdparty/phonon/mmf/abstractmediaplayer.cpp
index 6e7f458..83c534a 100644
--- a/src/3rdparty/phonon/mmf/abstractmediaplayer.cpp
+++ b/src/3rdparty/phonon/mmf/abstractmediaplayer.cpp
@@ -179,13 +179,20 @@ void MMF::AbstractMediaPlayer::seek(qint64 ms)
     case PlayingState:
     case LoadingState:
     {
-        const bool positionTimerWasRunning = m_positionTimer->isActive();
-        stopPositionTimer();
+        bool wasPlaying = false;
+        if (state() == PlayingState) {
+            stopPositionTimer();
+            doPause();
+            wasPlaying = true;
+        }
 
         doSeek(ms);
 
-        if (positionTimerWasRunning)
+        if(wasPlaying && state() != ErrorState) {
+            doPlay();
             startPositionTimer();
+        }
+
         break;
     }
     case BufferingState:
@@ -370,7 +377,6 @@ void MMF::AbstractMediaPlayer::doVolumeChanged()
     }
 }
 
-
 //-----------------------------------------------------------------------------
 // Protected functions
 //-----------------------------------------------------------------------------
diff --git a/src/3rdparty/phonon/mmf/mmf_videoplayer.cpp b/src/3rdparty/phonon/mmf/mmf_videoplayer.cpp
index 4a70d58..dab7505 100644
--- a/src/3rdparty/phonon/mmf/mmf_videoplayer.cpp
+++ b/src/3rdparty/phonon/mmf/mmf_videoplayer.cpp
@@ -142,24 +142,10 @@ void MMF::VideoPlayer::doSeek(qint64 ms)
 {
     TRACE_CONTEXT(VideoPlayer::doSeek, EVideoApi);
 
-    bool wasPlaying = false;
-    if (state() == PlayingState) {
-        // The call to SetPositionL does not have any effect if playback is
-        // ongoing, so we pause before seeking.
-        doPause();
-        wasPlaying = true;
-    }
-
     TRAPD(err, m_player->SetPositionL(TTimeIntervalMicroSeconds(ms * 1000)));
 
-    if (KErrNone == err) {
-        if (wasPlaying)
-            doPlay();
-    }
-    else {
-        TRACE("SetPositionL error %d", err);
+    if(KErrNone != err)
         setError(tr("Seek failed"), err);
-    }
 }
 
 int MMF::VideoPlayer::setDeviceVolume(int mmfVolume)