tests/auto/qgl/tst_qgl.cpp
changeset 3 41300fa6a67c
parent 0 1918ee327afb
child 4 3b1da2848fc7
--- a/tests/auto/qgl/tst_qgl.cpp	Tue Jan 26 12:42:25 2010 +0200
+++ b/tests/auto/qgl/tst_qgl.cpp	Tue Feb 02 00:43:10 2010 +0200
@@ -75,14 +75,15 @@
     void graphicsViewClipping();
     void partialGLWidgetUpdates_data();
     void partialGLWidgetUpdates();
+    void glWidgetWithAlpha();
     void glWidgetRendering();
+    void glFBOSimpleRendering();
     void glFBORendering();
     void multipleFBOInterleavedRendering();
     void glFBOUseInGLWidget();
     void glPBufferRendering();
     void glWidgetReparent();
     void glWidgetRenderPixmap();
-    void stackedFBOs();
     void colormap();
     void fboFormat();
     void testDontCrashOnDanglingResources();
@@ -118,6 +119,16 @@
     void setAutoBufferSwap(bool on) { QGLWidget::setAutoBufferSwap(on); }
 };
 
+static int appDefaultDepth()
+{
+    static int depth = 0;
+    if (depth == 0) {
+        QPixmap pm(1, 1);
+        depth = pm.depth();
+    }
+    return depth;
+}
+
 // Using INT_MIN and INT_MAX will cause failures on systems
 // where "int" is 64-bit, so use the explicit values instead.
 #define TEST_INT_MIN    (-2147483647 - 1)
@@ -241,15 +252,10 @@
 
     // bool QGLFormat::sampleBuffers()
     // void QGLFormat::setSampleBuffers(bool)
-#if !defined(QT_OPENGL_ES_2)
     QCOMPARE(false, obj1.sampleBuffers());
     QVERIFY(!obj1.testOption(QGL::SampleBuffers));
     QVERIFY(obj1.testOption(QGL::NoSampleBuffers));
-#else
-    QCOMPARE(true, obj1.sampleBuffers());
-    QVERIFY(obj1.testOption(QGL::SampleBuffers));
-    QVERIFY(!obj1.testOption(QGL::NoSampleBuffers));
-#endif
+
     obj1.setSampleBuffers(false);
     QCOMPARE(false, obj1.sampleBuffers());
     QVERIFY(obj1.testOption(QGL::NoSampleBuffers));
@@ -702,6 +708,79 @@
 #endif //QT_BUILD_INTERNAL
 }
 
+static bool fuzzyComparePixels(const QRgb testPixel, const QRgb refPixel, const char* file, int line, int x = -1, int y = -1)
+{
+    static int maxFuzz = 1;
+    static bool maxFuzzSet = false;
+
+    // On 16 bpp systems, we need to allow for more fuzz:
+    if (!maxFuzzSet) {
+        maxFuzzSet = true;
+        if (appDefaultDepth() < 24)
+            maxFuzz = 32;
+    }
+
+    int redFuzz = qAbs(qRed(testPixel) - qRed(refPixel));
+    int greenFuzz = qAbs(qGreen(testPixel) - qGreen(refPixel));
+    int blueFuzz = qAbs(qBlue(testPixel) - qBlue(refPixel));
+    int alphaFuzz = qAbs(qAlpha(testPixel) - qAlpha(refPixel));
+
+    if (refPixel != 0 && testPixel == 0) {
+        QString msg;
+        if (x >= 0) {
+            msg = QString("Test pixel [%1, %2] is null (black) when it should be (%3,%4,%5,%6)")
+                            .arg(x).arg(y)
+                            .arg(qRed(refPixel)).arg(qGreen(refPixel)).arg(qBlue(refPixel)).arg(qAlpha(refPixel));
+        } else {
+            msg = QString("Test pixel is null (black) when it should be (%2,%3,%4,%5)")
+                            .arg(qRed(refPixel)).arg(qGreen(refPixel)).arg(qBlue(refPixel)).arg(qAlpha(refPixel));
+        }
+
+        QTest::qFail(msg.toLatin1(), file, line);
+        return false;
+    }
+
+    if (redFuzz > maxFuzz || greenFuzz > maxFuzz || blueFuzz > maxFuzz || alphaFuzz > maxFuzz) {
+        QString msg;
+
+        if (x >= 0)
+            msg = QString("Pixel [%1,%2]: ").arg(x).arg(y);
+        else
+            msg = QString("Pixel ");
+
+        msg += QString("Max fuzz (%1) exceeded: (%2,%3,%4,%5) vs (%6,%7,%8,%9)")
+                      .arg(maxFuzz)
+                      .arg(qRed(testPixel)).arg(qGreen(testPixel)).arg(qBlue(testPixel)).arg(qAlpha(testPixel))
+                      .arg(qRed(refPixel)).arg(qGreen(refPixel)).arg(qBlue(refPixel)).arg(qAlpha(refPixel));
+        QTest::qFail(msg.toLatin1(), file, line);
+        return false;
+    }
+    return true;
+}
+
+static void fuzzyCompareImages(const QImage &testImage, const QImage &referenceImage, const char* file, int line)
+{
+    QCOMPARE(testImage.width(), referenceImage.width());
+    QCOMPARE(testImage.height(), referenceImage.height());
+
+    for (int y = 0; y < testImage.height(); y++) {
+        for (int x = 0; x < testImage.width(); x++) {
+            if (!fuzzyComparePixels(testImage.pixel(x, y), referenceImage.pixel(x, y), file, line, x, y)) {
+                // Might as well save the images for easier debugging:
+                referenceImage.save("referenceImage.png");
+                testImage.save("testImage.png");
+                return;
+            }
+        }
+    }
+}
+
+#define QFUZZY_COMPARE_IMAGES(A,B) \
+            fuzzyCompareImages(A, B, __FILE__, __LINE__)
+
+#define QFUZZY_COMPARE_PIXELS(A,B) \
+            fuzzyComparePixels(A, B, __FILE__, __LINE__)
+
 class UnclippedWidget : public QWidget
 {
 public:
@@ -723,6 +802,9 @@
     scene.addWidget(widget)->setPos(0, 0);
 
     QGraphicsView view(&scene);
+#ifdef Q_WS_QWS
+    view.setWindowFlags(Qt::FramelessWindowHint);
+#endif
     view.resize(2*size, 2*size);
 
     QGLWidget *viewport = new QGLWidget;
@@ -747,7 +829,7 @@
     p.fillRect(QRect(0, 0, size, size), Qt::black);
     p.end();
 
-    QCOMPARE(image, expected);
+    QFUZZY_COMPARE_IMAGES(image, expected);
 }
 
 void tst_QGL::partialGLWidgetUpdates_data()
@@ -838,7 +920,18 @@
     p.fillRect(32, 32, 64, 64, Qt::blue);
     p.end();
 
-    QCOMPARE(fb, reference);
+    QFUZZY_COMPARE_IMAGES(fb, reference);
+}
+
+void tst_QGL::glWidgetWithAlpha()
+{
+    QGLWidget* w = new QGLWidget(QGLFormat(QGL::AlphaChannel));
+    w->show();
+#ifdef Q_WS_X11
+    qt_x11_wait_for_window_manager(w);
+#endif
+
+    delete w;
 }
 
 class GLWidget : public QGLWidget
@@ -857,8 +950,8 @@
 
         // This test only ensures it's possible to paint onto a QGLWidget. Full
         // paint engine feature testing is way out of scope!
+        p.fillRect(-1, -1, width()+2, height()+2, Qt::red);
 
-        p.fillRect(0, 0, width(), height(), Qt::red);
         // No p.end() or swap buffers, should be done automatically
     }
 
@@ -867,6 +960,10 @@
 void tst_QGL::glWidgetRendering()
 {
     GLWidget w;
+#ifdef Q_WS_QWS
+    w.setWindowFlags(Qt::FramelessWindowHint);
+#endif
+    w.setGeometry(100, 100, 200, 200);
     w.show();
 
 #ifdef Q_WS_X11
@@ -881,7 +978,37 @@
     QImage reference(fb.size(), QImage::Format_RGB32);
     reference.fill(0xffff0000);
 
-    QCOMPARE(fb, reference);
+    QFUZZY_COMPARE_IMAGES(fb, reference);
+}
+
+void tst_QGL::glFBOSimpleRendering()
+{
+    if (!QGLFramebufferObject::hasOpenGLFramebufferObjects())
+        QSKIP("QGLFramebufferObject not supported on this platform", SkipSingle);
+
+    QGLWidget glw;
+    glw.makeCurrent();
+
+    // No multisample with combined depth/stencil attachment:
+    QGLFramebufferObjectFormat fboFormat;
+    fboFormat.setAttachment(QGLFramebufferObject::NoAttachment);
+
+    // Don't complicate things by using NPOT:
+    QGLFramebufferObject *fbo = new QGLFramebufferObject(256, 128, fboFormat);
+
+    fbo->bind();
+
+    glClearColor(1.0, 0.0, 0.0, 1.0);
+    glClear(GL_COLOR_BUFFER_BIT);
+    glFinish();
+
+    QImage fb = fbo->toImage().convertToFormat(QImage::Format_RGB32);
+    QImage reference(fb.size(), QImage::Format_RGB32);
+    reference.fill(0xffff0000);
+
+    QFUZZY_COMPARE_IMAGES(fb, reference);
+
+    delete fbo;
 }
 
 // NOTE: This tests that CombinedDepthStencil attachment works by assuming the
@@ -936,14 +1063,14 @@
     // As we're doing more than trivial painting, we can't just compare to
     // an image rendered with raster. Instead, we sample at well-defined
     // test-points:
-    QCOMPARE(fb.pixel(39, 64), QColor(Qt::red).rgb());
-    QCOMPARE(fb.pixel(89, 64), QColor(Qt::red).rgb());
-    QCOMPARE(fb.pixel(64, 39), QColor(Qt::blue).rgb());
-    QCOMPARE(fb.pixel(64, 89), QColor(Qt::blue).rgb());
+    QFUZZY_COMPARE_PIXELS(fb.pixel(39, 64), QColor(Qt::red).rgb());
+    QFUZZY_COMPARE_PIXELS(fb.pixel(89, 64), QColor(Qt::red).rgb());
+    QFUZZY_COMPARE_PIXELS(fb.pixel(64, 39), QColor(Qt::blue).rgb());
+    QFUZZY_COMPARE_PIXELS(fb.pixel(64, 89), QColor(Qt::blue).rgb());
 
-    QCOMPARE(fb.pixel(167, 39), QColor(Qt::red).rgb());
-    QCOMPARE(fb.pixel(217, 39), QColor(Qt::red).rgb());
-    QCOMPARE(fb.pixel(192, 64), QColor(Qt::green).rgb());
+    QFUZZY_COMPARE_PIXELS(fb.pixel(167, 39), QColor(Qt::red).rgb());
+    QFUZZY_COMPARE_PIXELS(fb.pixel(217, 39), QColor(Qt::red).rgb());
+    QFUZZY_COMPARE_PIXELS(fb.pixel(192, 64), QColor(Qt::green).rgb());
 }
 
 
@@ -1034,29 +1161,29 @@
     // As we're doing more than trivial painting, we can't just compare to
     // an image rendered with raster. Instead, we sample at well-defined
     // test-points:
-    QCOMPARE(fb1.pixel(39, 64), QColor(Qt::red).rgb());
-    QCOMPARE(fb1.pixel(89, 64), QColor(Qt::red).rgb());
-    QCOMPARE(fb1.pixel(64, 39), QColor(Qt::blue).rgb());
-    QCOMPARE(fb1.pixel(64, 89), QColor(Qt::blue).rgb());
-    QCOMPARE(fb1.pixel(167, 39), QColor(Qt::red).rgb());
-    QCOMPARE(fb1.pixel(217, 39), QColor(Qt::red).rgb());
-    QCOMPARE(fb1.pixel(192, 64), QColor(Qt::green).rgb());
+    QFUZZY_COMPARE_PIXELS(fb1.pixel(39, 64), QColor(Qt::red).rgb());
+    QFUZZY_COMPARE_PIXELS(fb1.pixel(89, 64), QColor(Qt::red).rgb());
+    QFUZZY_COMPARE_PIXELS(fb1.pixel(64, 39), QColor(Qt::blue).rgb());
+    QFUZZY_COMPARE_PIXELS(fb1.pixel(64, 89), QColor(Qt::blue).rgb());
+    QFUZZY_COMPARE_PIXELS(fb1.pixel(167, 39), QColor(Qt::red).rgb());
+    QFUZZY_COMPARE_PIXELS(fb1.pixel(217, 39), QColor(Qt::red).rgb());
+    QFUZZY_COMPARE_PIXELS(fb1.pixel(192, 64), QColor(Qt::green).rgb());
 
-    QCOMPARE(fb2.pixel(39, 64), QColor(Qt::green).rgb());
-    QCOMPARE(fb2.pixel(89, 64), QColor(Qt::green).rgb());
-    QCOMPARE(fb2.pixel(64, 39), QColor(Qt::red).rgb());
-    QCOMPARE(fb2.pixel(64, 89), QColor(Qt::red).rgb());
-    QCOMPARE(fb2.pixel(167, 39), QColor(Qt::green).rgb());
-    QCOMPARE(fb2.pixel(217, 39), QColor(Qt::green).rgb());
-    QCOMPARE(fb2.pixel(192, 64), QColor(Qt::blue).rgb());
+    QFUZZY_COMPARE_PIXELS(fb2.pixel(39, 64), QColor(Qt::green).rgb());
+    QFUZZY_COMPARE_PIXELS(fb2.pixel(89, 64), QColor(Qt::green).rgb());
+    QFUZZY_COMPARE_PIXELS(fb2.pixel(64, 39), QColor(Qt::red).rgb());
+    QFUZZY_COMPARE_PIXELS(fb2.pixel(64, 89), QColor(Qt::red).rgb());
+    QFUZZY_COMPARE_PIXELS(fb2.pixel(167, 39), QColor(Qt::green).rgb());
+    QFUZZY_COMPARE_PIXELS(fb2.pixel(217, 39), QColor(Qt::green).rgb());
+    QFUZZY_COMPARE_PIXELS(fb2.pixel(192, 64), QColor(Qt::blue).rgb());
 
-    QCOMPARE(fb3.pixel(39, 64), QColor(Qt::blue).rgb());
-    QCOMPARE(fb3.pixel(89, 64), QColor(Qt::blue).rgb());
-    QCOMPARE(fb3.pixel(64, 39), QColor(Qt::green).rgb());
-    QCOMPARE(fb3.pixel(64, 89), QColor(Qt::green).rgb());
-    QCOMPARE(fb3.pixel(167, 39), QColor(Qt::blue).rgb());
-    QCOMPARE(fb3.pixel(217, 39), QColor(Qt::blue).rgb());
-    QCOMPARE(fb3.pixel(192, 64), QColor(Qt::red).rgb());
+    QFUZZY_COMPARE_PIXELS(fb3.pixel(39, 64), QColor(Qt::blue).rgb());
+    QFUZZY_COMPARE_PIXELS(fb3.pixel(89, 64), QColor(Qt::blue).rgb());
+    QFUZZY_COMPARE_PIXELS(fb3.pixel(64, 39), QColor(Qt::green).rgb());
+    QFUZZY_COMPARE_PIXELS(fb3.pixel(64, 89), QColor(Qt::green).rgb());
+    QFUZZY_COMPARE_PIXELS(fb3.pixel(167, 39), QColor(Qt::blue).rgb());
+    QFUZZY_COMPARE_PIXELS(fb3.pixel(217, 39), QColor(Qt::blue).rgb());
+    QFUZZY_COMPARE_PIXELS(fb3.pixel(192, 64), QColor(Qt::red).rgb());
 }
 
 class FBOUseInGLWidget : public QGLWidget
@@ -1076,11 +1203,11 @@
 
         QPainter fboPainter;
         fboPainterBeginOk = fboPainter.begin(fbo);
-        fboPainter.fillRect(0, 0, 128, 128, Qt::red);
+        fboPainter.fillRect(-1, -1, 130, 130, Qt::red);
         fboPainter.end();
         fboImage = fbo->toImage();
 
-        widgetPainter.fillRect(rect(), Qt::blue);
+        widgetPainter.fillRect(-1, -1, width()+2, width()+2, Qt::blue);
 
         delete fbo;
     }
@@ -1093,6 +1220,9 @@
         QSKIP("QGLFramebufferObject not supported on this platform", SkipSingle);
 
     FBOUseInGLWidget w;
+#ifdef Q_WS_QWS
+    w.setWindowFlags(Qt::FramelessWindowHint);
+#endif
     w.resize(128, 128);
     w.show();
 
@@ -1107,11 +1237,11 @@
     QImage widgetFB = w.grabFrameBuffer(false);
     QImage widgetReference(widgetFB.size(), widgetFB.format());
     widgetReference.fill(0xff0000ff);
-    QCOMPARE(widgetFB, widgetReference);
+    QFUZZY_COMPARE_IMAGES(widgetFB, widgetReference);
 
     QImage fboReference(w.fboImage.size(), w.fboImage.format());
     fboReference.fill(0xffff0000);
-    QCOMPARE(w.fboImage, fboReference);
+    QFUZZY_COMPARE_IMAGES(w.fboImage, fboReference);
 }
 
 void tst_QGL::glWidgetReparent()
@@ -1205,113 +1335,9 @@
     QImage reference(fb.size(), QImage::Format_RGB32);
     reference.fill(0xffff0000);
 
-    QCOMPARE(fb, reference);
+    QFUZZY_COMPARE_IMAGES(fb, reference);
 }
 
-
-// When using multiple FBOs at the same time, unbinding one FBO should re-bind the
-// previous. I.e. It should be possible to have a stack of FBOs where pop'ing there
-// top re-binds the one underneeth.
-void tst_QGL::stackedFBOs()
-{
-    if (!QGLFramebufferObject::hasOpenGLFramebufferObjects())
-        QSKIP("QGLFramebufferObject not supported on this platform", SkipSingle);
-
-    QGLWidget glw;
-    glw.show();
-
-#ifdef Q_WS_X11
-    qt_x11_wait_for_window_manager(&glw);
-#endif
-    QTest::qWait(200);
-
-    glw.makeCurrent();
-
-    // No multisample with combined depth/stencil attachment:
-    QGLFramebufferObjectFormat fboFormat;
-    fboFormat.setAttachment(QGLFramebufferObject::CombinedDepthStencil);
-
-    // Don't complicate things by using NPOT:
-    QGLFramebufferObject *fbo1 = new QGLFramebufferObject(128, 128, fboFormat);
-    QGLFramebufferObject *fbo2 = new QGLFramebufferObject(128, 128, fboFormat);
-    QGLFramebufferObject *fbo3 = new QGLFramebufferObject(128, 128, fboFormat);
-
-    glClearColor(1.0, 0.0, 1.0, 1.0);
-    glClear(GL_COLOR_BUFFER_BIT);
-
-    fbo1->bind();
-        glClearColor(1.0, 0.0, 0.0, 1.0);
-        glClear(GL_COLOR_BUFFER_BIT);
-
-        fbo2->bind();
-            glClearColor(0.0, 1.0, 0.0, 1.0);
-            glClear(GL_COLOR_BUFFER_BIT);
-
-            fbo3->bind();
-                glClearColor(0.0, 0.0, 1.0, 1.0);
-                glClear(GL_COLOR_BUFFER_BIT);
-                glScissor(32, 32, 64, 64);
-                glEnable(GL_SCISSOR_TEST);
-                glClearColor(0.0, 1.0, 1.0, 1.0);
-                glClear(GL_COLOR_BUFFER_BIT);
-            fbo3->release();
-
-            // Scissor rect & test should be left untouched by the fbo release...
-            glClearColor(0.0, 0.0, 0.0, 1.0);
-            glClear(GL_COLOR_BUFFER_BIT);
-        fbo2->release();
-
-        glClearColor(1.0, 1.0, 1.0, 1.0);
-        glClear(GL_COLOR_BUFFER_BIT);
-    fbo1->release();
-
-    glClearColor(1.0, 1.0, 0.0, 1.0);
-    glClear(GL_COLOR_BUFFER_BIT);
-
-    glw.swapBuffers();
-
-    QImage widgetFB = glw.grabFrameBuffer(false).convertToFormat(QImage::Format_RGB32);
-    QImage fb1 = fbo1->toImage().convertToFormat(QImage::Format_RGB32);
-    QImage fb2 = fbo2->toImage().convertToFormat(QImage::Format_RGB32);
-    QImage fb3 = fbo3->toImage().convertToFormat(QImage::Format_RGB32);
-
-    delete fbo1;
-    delete fbo2;
-    delete fbo3;
-
-    QImage widgetReference(widgetFB.size(), widgetFB.format());
-    QImage fb1Reference(fb1.size(), fb1.format());
-    QImage fb2Reference(fb2.size(), fb2.format());
-    QImage fb3Reference(fb3.size(), fb3.format());
-
-    QPainter widgetReferencePainter(&widgetReference);
-    QPainter fb1ReferencePainter(&fb1Reference);
-    QPainter fb2ReferencePainter(&fb2Reference);
-    QPainter fb3ReferencePainter(&fb3Reference);
-
-    widgetReferencePainter.fillRect(0, 0, widgetReference.width(), widgetReference.height(), Qt::magenta);
-    fb1ReferencePainter.fillRect(0, 0, fb1Reference.width(), fb1Reference.height(), Qt::red);
-    fb2ReferencePainter.fillRect(0, 0, fb2Reference.width(), fb2Reference.height(), Qt::green);
-    fb3ReferencePainter.fillRect(0, 0, fb3Reference.width(), fb3Reference.height(), Qt::blue);
-
-    // Flip y-coords to match GL for the widget (which can be any size)
-    widgetReferencePainter.fillRect(32, glw.height() - 96, 64, 64, Qt::yellow);
-    fb1ReferencePainter.fillRect(32, 32, 64, 64, Qt::white);
-    fb2ReferencePainter.fillRect(32, 32, 64, 64, Qt::black);
-    fb3ReferencePainter.fillRect(32, 32, 64, 64, Qt::cyan);
-
-    widgetReferencePainter.end();
-    fb1ReferencePainter.end();
-    fb2ReferencePainter.end();
-    fb3ReferencePainter.end();
-
-    QCOMPARE(widgetFB, widgetReference);
-    QCOMPARE(fb1, fb1Reference);
-    QCOMPARE(fb2, fb2Reference);
-    QCOMPARE(fb3, fb3Reference);
-}
-
-
 class ColormapExtended : public QGLColormap
 {
 public:
@@ -1583,6 +1609,9 @@
 void tst_QGL::replaceClipping()
 {
     ReplaceClippingGLWidget glw;
+#ifdef Q_WS_QWS
+    glw.setWindowFlags(Qt::FramelessWindowHint);
+#endif
     glw.resize(300, 300);
     glw.show();
 
@@ -1598,7 +1627,13 @@
 
     const QImage widgetFB = glw.grabFrameBuffer(false).convertToFormat(QImage::Format_RGB32);
 
-    QCOMPARE(widgetFB, reference);
+    // Sample pixels in a grid pattern which avoids false failures due to
+    // off-by-one pixel errors on some buggy GL implementations
+    for (int x = 25; x < reference.width(); x += 50) {
+        for (int y = 25; y < reference.width(); y += 50) {
+            QFUZZY_COMPARE_PIXELS(widgetFB.pixel(x, y), reference.pixel(x, y));
+        }
+    }
 }
 
 class ClipTestGLWidget : public QGLWidget
@@ -1606,7 +1641,7 @@
 public:
     void paint(QPainter *painter)
     {
-        painter->fillRect(rect(), Qt::white);
+        painter->fillRect(-1, -1, width()+2, height()+2, Qt::white);
         painter->setClipRect(10, 10, width()-20, height()-20);
         painter->fillRect(rect(), Qt::cyan);
 
@@ -1708,6 +1743,9 @@
 void tst_QGL::clipTest()
 {
     ClipTestGLWidget glw;
+#ifdef Q_WS_QWS
+    glw.setWindowFlags(Qt::FramelessWindowHint);
+#endif
     glw.resize(220, 220);
     glw.show();
 
@@ -1723,7 +1761,13 @@
 
     const QImage widgetFB = glw.grabFrameBuffer(false).convertToFormat(QImage::Format_RGB32);
 
-    QCOMPARE(widgetFB, reference);
+    // Sample pixels in a grid pattern which avoids false failures due to
+    // off-by-one pixel errors on some buggy GL implementations
+    for (int x = 2; x < reference.width(); x += 5) {
+        for (int y = 2; y < reference.width(); y += 5) {
+            QFUZZY_COMPARE_PIXELS(widgetFB.pixel(x, y), reference.pixel(x, y));
+        }
+    }
 }
 
 void tst_QGL::destroyFBOAfterContext()
@@ -1805,12 +1849,14 @@
     QVERIFY(qt_shared_test()->value(glw1->context()) == res1);
 
     // Create another context that shares with the first.
+    QVERIFY(!glw1->isSharing());
     QGLWidget *glw2 = new QGLWidget(0, glw1);
     if (!glw2->isSharing()) {
         delete glw2;
         delete glw1;
         QSKIP("Context sharing is not supported", SkipSingle);
     }
+    QVERIFY(glw1->isSharing());
     QVERIFY(glw1->context() != glw2->context());
 
     // Check that the first context's resource is also on the second.
@@ -1842,6 +1888,7 @@
 
     // Create a third context, not sharing with the others.
     QGLWidget *glw3 = new QGLWidget();
+    QVERIFY(!glw3->isSharing());
 
     // Create a guard on the standalone context.
     QGLSharedResourceGuard guard3(glw3->context());
@@ -1890,6 +1937,9 @@
     // Delete the first context.
     delete glw1;
 
+    // The second context should no longer register as sharing.
+    QVERIFY(!glw2->isSharing());
+
     // The first context's resource should transfer to the second context.
     QCOMPARE(tst_QGLResource::deletions, 0);
     QVERIFY(qt_shared_test()->value(glw2->context()) == res1);