Merge remote-tracking branch 'origin/4.7' into qt-4.8-from-4.7

Conflicts:
	doc/src/getting-started/installation.qdoc
	doc/src/platforms/platform-notes.qdoc
	src/corelib/tools/qlocale_symbian.cpp
	src/gui/kernel/qwidget_p.h
	src/network/access/qnetworkaccesshttpbackend.cpp
	src/opengl/qgl.cpp
	src/plugins/bearer/symbian/qnetworksession_impl.cpp

13 files changed, 238 insertions, 49 deletions

diff --git a/src/declarative/qml/qdeclarativeimport.cpp b/src/declarative/qml/qdeclarativeimport.cpp
index bf261ef242..c2f00865ef 100644
--- a/src/declarative/qml/qdeclarativeimport.cpp
+++ b/src/declarative/qml/qdeclarativeimport.cpp
@@ -46,6 +46,7 @@
 #include <QtCore/qfileinfo.h>
 #include <QtCore/qpluginloader.h>
 #include <QtCore/qlibraryinfo.h>
+#include <QtCore/qalgorithms.h>
 #include <QtDeclarative/qdeclarativeextensioninterface.h>
 #include <private/qdeclarativeglobal_p.h>
 #include <private/qdeclarativetypenamecache_p.h>
@@ -734,8 +735,12 @@ QDeclarativeImportDatabase::QDeclarativeImportDatabase(QDeclarativeEngine *e)
         }
         RFs& fs = qt_s60GetRFs();
         TPtrC tempPathPtr(reinterpret_cast<const TText*> (tempPath.constData()));
+        // Symbian searches should start from Y:. Fix start drive otherwise TFindFile starts from the session drive
+        _LIT(KStartDir, "Y:");
+        TFileName dirPath(KStartDir);
+        dirPath.Append(tempPathPtr);
         TFindFile finder(fs);
-        TInt err = finder.FindByDir(tempPathPtr, tempPathPtr);
+        TInt err = finder.FindByDir(tempPathPtr, dirPath);
         while (err == KErrNone) {
             QString foundDir(reinterpret_cast<const QChar *>(finder.File().Ptr()),
                              finder.File().Length());
@@ -743,6 +748,9 @@ QDeclarativeImportDatabase::QDeclarativeImportDatabase(QDeclarativeEngine *e)
             addImportPath(foundDir);
             err = finder.Find();
         }
+        // TFindFile found the directories in the order we want, but addImportPath reverses it.
+        // Reverse the order again to get it right.
+        QAlgorithmsPrivate::qReverse(fileImportPath.begin(), fileImportPath.end());
     } else {
         addImportPath(installImportsPath);
     }
diff --git a/src/declarative/qml/qdeclarativepropertycache_p.h b/src/declarative/qml/qdeclarativepropertycache_p.h
index 581f5197f4..c648d25cb7 100644
--- a/src/declarative/qml/qdeclarativepropertycache_p.h
+++ b/src/declarative/qml/qdeclarativepropertycache_p.h
@@ -111,7 +111,7 @@ public:
             int relatedIndex; // When IsFunction
         };
         uint overrideIndexIsProperty : 1;
-        int overrideIndex : 31;
+        signed int overrideIndex : 31;
         int revision; 
         int metaObjectOffset;
 
diff --git a/src/gui/egl/qegl.cpp b/src/gui/egl/qegl.cpp
index 2a37d45089..6fe1c8c446 100644
--- a/src/gui/egl/qegl.cpp
+++ b/src/gui/egl/qegl.cpp
@@ -684,6 +684,37 @@ EGLSurface QEgl::createSurface(QPaintDevice *device, EGLConfig cfg, const QEglPr
     else
         props = 0;
     EGLSurface surf;
+#ifdef Q_OS_SYMBIAN
+    // On Symbian there might be situations (especially on 32MB GPU devices)
+    // where Qt is trying to create EGL surface while some other application
+    // is still holding all available GPU memory but is about to release it
+    // soon. For an example when exiting native video recorder and going back to
+    // Qt application behind it. Video stack tear down takes some time and Qt
+    // app might be too quick in reserving its EGL surface and thus running out
+    // of GPU memory right away. So if EGL surface creation fails due to bad
+    // alloc, let's try recreating it four times within ~1 second if needed.
+    // This strategy gives some time for video recorder to tear down its stack
+    // and a chance to Qt for creating a valid surface.
+    int tries = 4;
+    while(tries--) {
+        if (devType == QInternal::Widget)
+            surf = eglCreateWindowSurface(QEgl::display(), cfg, windowDrawable, props);
+        else
+            surf = eglCreatePixmapSurface(QEgl::display(), cfg, pixmapDrawable, props);
+        if (surf == EGL_NO_SURFACE) {
+            EGLint error = eglGetError();
+            if (error == EGL_BAD_ALLOC) {
+                if (tries) {
+                    User::After(1000 * 250); // 250ms
+                    continue;
+                }
+            }
+            qWarning("QEglContext::createSurface(): Unable to create EGL surface, error = 0x%x", error);
+        } else {
+            break;
+        }
+    }
+#else
     if (devType == QInternal::Widget)
         surf = eglCreateWindowSurface(QEgl::display(), cfg, windowDrawable, props);
     else
@@ -691,6 +722,7 @@ EGLSurface QEgl::createSurface(QPaintDevice *device, EGLConfig cfg, const QEglPr
     if (surf == EGL_NO_SURFACE) {
         qWarning("QEglContext::createSurface(): Unable to create EGL surface, error = 0x%x", eglGetError());
     }
+#endif
     return surf;
 }
 #endif
diff --git a/src/gui/kernel/qcursor_win.cpp b/src/gui/kernel/qcursor_win.cpp
index cef83f5a1b..a68472c584 100644
--- a/src/gui/kernel/qcursor_win.cpp
+++ b/src/gui/kernel/qcursor_win.cpp
@@ -477,7 +477,7 @@ void QCursorData::update()
         QPixmap pixmap = QApplicationPrivate::instance()->getPixmapCursor(cshape);
         hcurs = create32BitCursor(pixmap, hx, hy);
     }
-        break;
+        return;
     default:
         qWarning("QCursor::update: Invalid cursor shape %d", cshape);
         return;
diff --git a/src/gui/kernel/qwidget.cpp b/src/gui/kernel/qwidget.cpp
index 0aa1dfa283..9b5a28326f 100644
--- a/src/gui/kernel/qwidget.cpp
+++ b/src/gui/kernel/qwidget.cpp
@@ -2260,10 +2260,16 @@ void QWidgetPrivate::updateIsOpaque()
 #endif
 
 #ifdef Q_WS_S60
-    if (q->windowType() == Qt::Dialog && q->testAttribute(Qt::WA_TranslucentBackground)
-                && S60->avkonComponentsSupportTransparency) {
-        setOpaque(false);
-        return;
+    if (q->testAttribute(Qt::WA_TranslucentBackground)) {
+        if (q->windowType() & Qt::Dialog || q->windowType() & Qt::Popup) {
+            if (S60->avkonComponentsSupportTransparency) {
+                setOpaque(false);
+                return;
+            }
+        } else {
+            setOpaque(false);
+            return;
+        }
     }
 #endif
 
@@ -2283,11 +2289,16 @@ void QWidgetPrivate::updateIsOpaque()
     }
 
     if (q->isWindow() && !q->testAttribute(Qt::WA_NoSystemBackground)) {
+#ifdef Q_WS_S60
+        setOpaque(true);
+        return;
+#else
         const QBrush &windowBrush = q->palette().brush(QPalette::Window);
         if (windowBrush.style() != Qt::NoBrush && windowBrush.isOpaque()) {
             setOpaque(true);
             return;
         }
+#endif
     }
     setOpaque(false);
 }
@@ -10948,11 +10959,14 @@ void QWidget::setAttribute(Qt::WidgetAttribute attribute, bool on)
         }
         break;
     case Qt::WA_TranslucentBackground:
+#if defined(Q_OS_SYMBIAN)
+        setAttribute(Qt::WA_NoSystemBackground, on);
+#else
         if (on) {
             setAttribute(Qt::WA_NoSystemBackground);
             d->updateIsTranslucent();
         }
-
+#endif
         break;
     case Qt::WA_AcceptTouchEvents:
 #if defined(Q_WS_WIN) || defined(Q_WS_MAC) || defined(Q_OS_SYMBIAN)
diff --git a/src/gui/kernel/qwidget_p.h b/src/gui/kernel/qwidget_p.h
index aefffb6ceb..9ac94795d5 100644
--- a/src/gui/kernel/qwidget_p.h
+++ b/src/gui/kernel/qwidget_p.h
@@ -233,6 +233,7 @@ struct QTLWExtra {
     uint inExpose : 1; // Prevents drawing recursion
     uint nativeWindowTransparencyEnabled : 1; // Tracks native window transparency
     uint forcedToRaster : 1;
+    uint noSystemRotationDisabled : 1;
 #elif defined(Q_WS_QPA)
     QPlatformWindow *platformWindow;
     QPlatformWindowFormat platformWindowFormat;
diff --git a/src/gui/kernel/qwidget_s60.cpp b/src/gui/kernel/qwidget_s60.cpp
index e06b625812..00661ae7e3 100644
--- a/src/gui/kernel/qwidget_s60.cpp
+++ b/src/gui/kernel/qwidget_s60.cpp
@@ -804,19 +804,12 @@ void QWidgetPrivate::setConstraints_sys()
 void QWidgetPrivate::s60UpdateIsOpaque()
 {
     Q_Q(QWidget);
-
     if (!q->testAttribute(Qt::WA_WState_Created))
         return;
-
     const bool writeAlpha = extraData()->nativePaintMode == QWExtra::BlitWriteAlpha;
-    if (!q->testAttribute(Qt::WA_TranslucentBackground) && !writeAlpha)
-        return;
     const bool requireAlphaChannel = !isOpaque || writeAlpha;
-
     createTLExtra();
-
     RWindow *const window = static_cast<RWindow *>(q->effectiveWinId()->DrawableWindow());
-
 #ifdef Q_SYMBIAN_SEMITRANSPARENT_BG_SURFACE
     if (QApplicationPrivate::instance()->useTranslucentEGLSurfaces
             && !extra->topextra->forcedToRaster) {
@@ -825,25 +818,47 @@ void QWidgetPrivate::s60UpdateIsOpaque()
         return;
     }
 #endif
+    const bool recreateBackingStore = extra->topextra->backingStore.data() && (
+                                          QApplicationPrivate::graphics_system_name == QLatin1String("openvg") ||
+                                          QApplicationPrivate::graphics_system_name == QLatin1String("opengl")
+                                      );
     if (requireAlphaChannel) {
-        const TDisplayMode displayMode = static_cast<TDisplayMode>(window->SetRequiredDisplayMode(EColor16MA));
-        if (window->SetTransparencyAlphaChannel() == KErrNone) {
+        window->SetRequiredDisplayMode(EColor16MA);
+        if (window->SetTransparencyAlphaChannel() == KErrNone)
             window->SetBackgroundColor(TRgb(255, 255, 255, 0));
-            extra->topextra->nativeWindowTransparencyEnabled = 1;
-            if (extra->topextra->backingStore.data() && (
-                    QApplicationPrivate::graphics_system_name == QLatin1String("openvg")
-                    || QApplicationPrivate::graphics_system_name == QLatin1String("opengl"))) {
-                // Semi-transparent EGL surfaces aren't supported. We need to
-                // recreate backing store to get translucent surface (raster surface).
-                extra->topextra->backingStore.create(q);
-                extra->topextra->backingStore.registerWidget(q);
-                // FixNativeOrientation() will not work without an EGL surface.
+    } else {
+        if (recreateBackingStore) {
+            // Clear the UI surface to ensure that the EGL surface content is visible
+            CWsScreenDevice *screenDevice = S60->screenDevice(q);
+            QScopedPointer<CWindowGc> gc(new CWindowGc(screenDevice));
+            const int err = gc->Construct();
+            if (!err) {
+                gc->Activate(*window);
+                window->BeginRedraw();
+                gc->SetDrawMode(CWindowGc::EDrawModeWriteAlpha);
+                gc->SetBrushColor(TRgb(0, 0, 0, 0));
+                gc->Clear(TRect(0, 0, q->width(), q->height()));
+                window->EndRedraw();
+            }
+        }
+        if (extra->topextra->nativeWindowTransparencyEnabled)
+            window->SetTransparentRegion(TRegionFix<1>());
+    }
+    extra->topextra->nativeWindowTransparencyEnabled = requireAlphaChannel;
+    if (recreateBackingStore) {
+        extra->topextra->backingStore.create(q);
+        extra->topextra->backingStore.registerWidget(q);
+        bool noSystemRotationDisabled = false;
+        if (requireAlphaChannel) {
+            if (q->testAttribute(Qt::WA_SymbianNoSystemRotation)) {
+                // FixNativeOrientation() will not work without an EGL surface
                 q->setAttribute(Qt::WA_SymbianNoSystemRotation, false);
+                noSystemRotationDisabled = true;
             }
+        } else {
+            q->setAttribute(Qt::WA_SymbianNoSystemRotation, extra->topextra->noSystemRotationDisabled);
         }
-    } else if (extra->topextra->nativeWindowTransparencyEnabled) {
-        window->SetTransparentRegion(TRegionFix<1>());
-        extra->topextra->nativeWindowTransparencyEnabled = 0;
+        extra->topextra->noSystemRotationDisabled = noSystemRotationDisabled;
     }
 }
 
@@ -1004,6 +1019,7 @@ void QWidgetPrivate::createTLSysExtra()
     extra->topextra->inExpose = 0;
     extra->topextra->nativeWindowTransparencyEnabled = 0;
     extra->topextra->forcedToRaster = 0;
+    extra->topextra->noSystemRotationDisabled = 0;
 }
 
 void QWidgetPrivate::deleteTLSysExtra()
diff --git a/src/gui/painting/qgraphicssystemex_symbian.cpp b/src/gui/painting/qgraphicssystemex_symbian.cpp
index 4469704668..32e040fdc8 100644
--- a/src/gui/painting/qgraphicssystemex_symbian.cpp
+++ b/src/gui/painting/qgraphicssystemex_symbian.cpp
@@ -46,31 +46,108 @@
 
 #include <e32property.h>
 
+#ifdef Q_SYMBIAN_SUPPORTS_SURFACES
+#include "private/qegl_p.h"
+#endif
+
 QT_BEGIN_NAMESPACE
 
 static bool bcm2727Initialized = false;
 static bool bcm2727 = false;
 
+#ifdef Q_SYMBIAN_SUPPORTS_SURFACES
+typedef EGLBoolean (*NOK_resource_profiling)(EGLDisplay, EGLint, EGLint*, EGLint, EGLint*);
+#define EGL_PROF_TOTAL_MEMORY_NOK 0x3070
+#endif
+
+// Detect if Qt is running on BCM2727 chip.
+// BCM2727 is a special case on Symbian because
+// it has only 32MB GPU memory which exposes
+// significant limitations to hw accelerated UI.
 bool QSymbianGraphicsSystemEx::hasBCM2727()
 {
     if (bcm2727Initialized)
         return bcm2727;
 
-    const TUid KIvePropertyCat = {0x2726beef};
-    enum TIvePropertyChipType {
-        EVCBCM2727B1 = 0x00000000,
-        EVCBCM2763A0 = 0x04000100,
-        EVCBCM2763B0 = 0x04000102,
-        EVCBCM2763C0 = 0x04000103,
-        EVCBCM2763C1 = 0x04000104,
-        EVCBCMUnknown = 0x7fffffff
-    };
-
-    TInt chipType = EVCBCMUnknown;
-    if (RProperty::Get(KIvePropertyCat, 0, chipType) == KErrNone) {
-        if (chipType == EVCBCM2727B1)
+#ifdef Q_SYMBIAN_SUPPORTS_SURFACES
+    EGLDisplay display = QEgl::display();
+#if 1
+    // Hacky but fast ~0ms.
+    const char* vendor = eglQueryString(display, EGL_VENDOR);
+    if (strstr(vendor, "Broadcom")) {
+        const TUid KIvePropertyCat = {0x2726beef};
+        enum TIvePropertyChipType {
+            EVCBCM2727B1 = 0x00000000,
+            EVCBCM2763A0 = 0x04000100,
+            EVCBCM2763B0 = 0x04000102,
+            EVCBCM2763C0 = 0x04000103,
+            EVCBCM2763C1 = 0x04000104,
+            EVCBCMUnknown = 0x7fffffff
+        };
+
+        // Broadcom driver publishes KIvePropertyCat PS key on
+        // devices which are running on BCM2727 chip and post Anna Symbian.
+        TInt chipType = EVCBCMUnknown;
+        if (RProperty::Get(KIvePropertyCat, 0, chipType) == KErrNone) {
+            if (chipType == EVCBCM2727B1)
+                bcm2727 = true;
+        } else if (QSysInfo::symbianVersion() <= QSysInfo::SV_SF_3) {
+            // Device is running on Symbian Anna or older Symbian^3 in which
+            // KIvePropertyCat is not published. These ones are always 32MB devices.
+            bcm2727 = true;
+        } else {
+            // We have some other Broadcom chip on post Anna Symbian.
+            // Should have > 32MB GPU memory.
+        }
+    }
+#else
+    // Fool proof but takes 15-20ms and we don't want this delay on app startup...
+
+    // All devices with <= 32MB GPU memory should be
+    // dealed in similar manner to BCM2727
+    // So let's query max GPU memory amount.
+    NOK_resource_profiling eglQueryProfilingData = (NOK_resource_profiling)eglGetProcAddress("eglQueryProfilingDataNOK");
+    if (eglQueryProfilingData) {
+        EGLint dataCount;
+        eglQueryProfilingData(display,
+                               EGL_PROF_QUERY_GLOBAL_BIT_NOK |
+                               EGL_PROF_QUERY_MEMORY_USAGE_BIT_NOK,
+                               NULL,
+                               0,
+                               (EGLint*)&dataCount);
+
+        // Allocate room for the profiling data
+        EGLint* profData = (EGLint*)malloc(dataCount * sizeof(EGLint));
+        memset(profData,0,dataCount * sizeof(EGLint));
+
+        // Retrieve the profiling data
+        eglQueryProfilingData(display,
+                              EGL_PROF_QUERY_GLOBAL_BIT_NOK |
+                              EGL_PROF_QUERY_MEMORY_USAGE_BIT_NOK,
+                              profData,
+                              dataCount,
+                              (EGLint*)&dataCount);
+
+        int totalMemory;
+        EGLint i = 0;
+        while (profData && i < dataCount) {
+            switch (profData[i++]) {
+                case EGL_PROF_TOTAL_MEMORY_NOK:
+                    totalMemory = profData[i++];
+                    break;
+                default:
+                    i++;
+            }
+        }
+
+        // ok, hasBCM2727() naming is a bit misleading but Qt must
+        // behave the same on all chips like BCM2727 (<= 32MB GPU memory)
+        // and our code (and others) are already using this function.
+        if (totalMemory <= 33554432)
             bcm2727 = true;
     }
+#endif
+#endif // Q_SYMBIAN_SUPPORTS_SURFACES
 
     bcm2727Initialized = true;
 
@@ -80,7 +157,9 @@ bool QSymbianGraphicsSystemEx::hasBCM2727()
 void QSymbianGraphicsSystemEx::releaseCachedGpuResources()
 {
     // Do nothing here
-    // This is implemented in graphics system specific plugin
+
+    // This virtual function should be implemented in graphics system specific
+    // plugin
 }
 
 void QSymbianGraphicsSystemEx::releaseAllGpuResources()
diff --git a/src/gui/widgets/qlinecontrol.cpp b/src/gui/widgets/qlinecontrol.cpp
index d58da37974..0af2e59c54 100644
--- a/src/gui/widgets/qlinecontrol.cpp
+++ b/src/gui/widgets/qlinecontrol.cpp
@@ -445,6 +445,8 @@ void QLineControl::moveCursor(int pos, bool mark)
 void QLineControl::processInputMethodEvent(QInputMethodEvent *event)
 {
     int priorState = 0;
+    int originalSelectionStart = m_selstart;
+    int originalSelectionEnd = m_selend;
     bool isGettingInput = !event->commitString().isEmpty()
             || event->preeditString() != preeditAreaText()
             || event->replacementLength() > 0;
@@ -523,6 +525,8 @@ void QLineControl::processInputMethodEvent(QInputMethodEvent *event)
     }
     m_textLayout.setAdditionalFormats(formats);
     updateDisplayText(/*force*/ true);
+    if (originalSelectionStart != m_selstart || originalSelectionEnd != m_selend)
+        emit selectionChanged();
     if (cursorPositionChanged)
         emitCursorPositionChanged();
     else if (m_preeditCursor != oldPreeditCursor)
diff --git a/src/network/access/qhttpnetworkreply.cpp b/src/network/access/qhttpnetworkreply.cpp
index 1a02200572..6173b39ff9 100644
--- a/src/network/access/qhttpnetworkreply.cpp
+++ b/src/network/access/qhttpnetworkreply.cpp
@@ -891,7 +891,7 @@ bool QHttpNetworkReplyPrivate::expectContent()
         || statusCode == 204 || statusCode == 304)
         return false;
     if (request.operation() == QHttpNetworkRequest::Head)
-        return !shouldEmitSignals();
+        return false; // no body expected for HEAD request
     qint64 expectedContentLength = contentLength();
     if (expectedContentLength == 0)
         return false;
diff --git a/src/network/access/qnetworkreplyimpl.cpp b/src/network/access/qnetworkreplyimpl.cpp
index 0b568d4d24..6f2daecdf0 100644
--- a/src/network/access/qnetworkreplyimpl.cpp
+++ b/src/network/access/qnetworkreplyimpl.cpp
@@ -471,6 +471,7 @@ bool QNetworkReplyImplPrivate::isCachingEnabled() const
 
 void QNetworkReplyImplPrivate::setCachingEnabled(bool enable)
 {
+    Q_Q(QNetworkReplyImpl);
     if (!enable && !cacheEnabled)
         return;                 // nothing to do
     if (enable && cacheEnabled)
@@ -493,15 +494,27 @@ void QNetworkReplyImplPrivate::setCachingEnabled(bool enable)
         networkCache()->remove(url);
         cacheSaveDevice = 0;
         cacheEnabled = false;
+        QObject::disconnect(networkCache(), SIGNAL(destroyed()), q, SLOT(_q_cacheDestroyed()));
     }
 }
 
+void QNetworkReplyImplPrivate::_q_cacheDestroyed()
+{
+    //destruction of cache invalidates cacheSaveDevice
+    cacheSaveDevice = 0;
+    cacheEnabled = false;
+}
+
 void QNetworkReplyImplPrivate::completeCacheSave()
 {
-    if (cacheEnabled && errorCode != QNetworkReplyImpl::NoError) {
-        networkCache()->remove(url);
-    } else if (cacheEnabled && cacheSaveDevice) {
-        networkCache()->insert(cacheSaveDevice);
+    Q_Q(QNetworkReplyImpl);
+    if (cacheEnabled) {
+        if (errorCode != QNetworkReplyImpl::NoError) {
+            networkCache()->remove(url);
+        } else if (cacheSaveDevice) {
+            networkCache()->insert(cacheSaveDevice);
+        }
+        QObject::disconnect(networkCache(), SIGNAL(destroyed()), q, SLOT(_q_cacheDestroyed()));
     }
     cacheSaveDevice = 0;
     cacheEnabled = false;
@@ -561,6 +574,8 @@ void QNetworkReplyImplPrivate::initCacheSaveDevice()
         networkCache()->remove(url);
         cacheSaveDevice = 0;
         cacheEnabled = false;
+    } else {
+        q->connect(networkCache(), SIGNAL(destroyed()), SLOT(_q_cacheDestroyed()));
     }
 }
 
diff --git a/src/network/access/qnetworkreplyimpl_p.h b/src/network/access/qnetworkreplyimpl_p.h
index 089c87e693..286d8eaf5e 100644
--- a/src/network/access/qnetworkreplyimpl_p.h
+++ b/src/network/access/qnetworkreplyimpl_p.h
@@ -104,6 +104,7 @@ public:
     Q_PRIVATE_SLOT(d_func(), void _q_networkSessionConnected())
     Q_PRIVATE_SLOT(d_func(), void _q_networkSessionFailed())
 #endif
+    Q_PRIVATE_SLOT(d_func(), void _q_cacheDestroyed())
 };
 
 class QNetworkReplyImplPrivate: public QNetworkReplyPrivate
@@ -140,6 +141,7 @@ public:
     void _q_networkSessionConnected();
     void _q_networkSessionFailed();
 #endif
+    void _q_cacheDestroyed();
 
     void setup(QNetworkAccessManager::Operation op, const QNetworkRequest &request,
                QIODevice *outgoingData);
diff --git a/src/opengl/qgl.cpp b/src/opengl/qgl.cpp
index cedccaa69b..423fa08a1f 100644
--- a/src/opengl/qgl.cpp
+++ b/src/opengl/qgl.cpp
@@ -103,6 +103,7 @@
 
 #ifdef Q_OS_SYMBIAN
 #include <private/qgltexturepool_p.h>
+#include <private/qeglcontext_p.h>
 #endif
 
 // #define QT_GL_CONTEXT_RESOURCE_DEBUG
@@ -3432,8 +3433,25 @@ const QGLContext* QGLContext::currentContext()
     return 0;
 #else
     QGLThreadContext *threadContext = qgl_context_storage.localData();
-    if (threadContext)
+    if (threadContext) {
+#ifdef Q_OS_SYMBIAN
+        // Query the current context and return null if it is different.
+        // This is needed to support mixed VG-GL rendering.
+        // QtOpenVG is free to make a QEglContext current at any time and
+        // QGLContext gets no notification that its underlying QEglContext is
+        // not current anymore. We query directly from EGL to be thread-safe.
+        // QEglContext does not store all the contexts per-thread.
+        if (threadContext->context) {
+            QEglContext *eglcontext = threadContext->context->d_func()->eglContext;
+            if (eglcontext) {
+                EGLContext ctx = eglcontext->context();
+                if (ctx != eglGetCurrentContext())
+                    return 0;
+            }
+        }
+#endif
         return threadContext->context;
+    }
     return 0;
 #endif //Q_WS_QPA
 }