4 files changed, 31 insertions, 3 deletions
diff --git a/src/gui/kernel/qopenglcontext.cpp b/src/gui/kernel/qopenglcontext.cpp
index 3fccd6ba9a..90e9235353 100644
--- a/src/gui/kernel/qopenglcontext.cpp
+++ b/src/gui/kernel/qopenglcontext.cpp
@@ -590,10 +590,10 @@ QVariant QOpenGLContext::nativeHandle() const
 */
 bool QOpenGLContext::create()
 {
-    if (isValid())
+    Q_D(QOpenGLContext);
+    if (d->platformGLContext)
         destroy();
 
-    Q_D(QOpenGLContext);
     d->platformGLContext = QGuiApplicationPrivate::platformIntegration()->createPlatformOpenGLContext(this);
     if (!d->platformGLContext)
         return false;
@@ -676,6 +676,15 @@ QOpenGLContext::~QOpenGLContext()
 /*!
     Returns if this context is valid, i.e. has been successfully created.
 
+    On some platforms the return value of \c false for a context that was
+    successfully created previously indicates that the OpenGL context was lost.
+
+    The typical way to handle context loss scenarios in applications is to
+    check via this function whenever makeCurrent() fails and returns \c false.
+    If this function then returns \c false, recreate the underlying native
+    OpenGL context by calling create(), call makeCurrent() again and then
+    reinitialize all OpenGL resources.
+
     \sa create()
 */
 bool QOpenGLContext::isValid() const
diff --git a/src/plugins/platforms/windows/qwindowseglcontext.cpp b/src/plugins/platforms/windows/qwindowseglcontext.cpp
index c0d0c1f77c..0872741e47 100644
--- a/src/plugins/platforms/windows/qwindowseglcontext.cpp
+++ b/src/plugins/platforms/windows/qwindowseglcontext.cpp
@@ -592,7 +592,17 @@ bool QWindowsEGLContext::makeCurrent(QPlatformSurface *surface)
             QWindowsEGLStaticContext::libEGL.eglSwapInterval(m_staticContext->display(), m_swapInterval);
         }
     } else {
-        qWarning("QWindowsEGLContext::makeCurrent: eglError: %x, this: %p \n", QWindowsEGLStaticContext::libEGL.eglGetError(), this);
+        int err = QWindowsEGLStaticContext::libEGL.eglGetError();
+        // EGL_CONTEXT_LOST (loss of the D3D device) is not necessarily fatal.
+        // Qt Quick is able to recover for example.
+        if (err == EGL_CONTEXT_LOST) {
+            m_eglContext = EGL_NO_CONTEXT;
+            qCDebug(lcQpaGl) << "Got EGL context lost in makeCurrent() for context" << this;
+            // Drop the surface. Will recreate on the next makeCurrent.
+            window->invalidateSurface();
+        } else {
+            qWarning("QWindowsEGLContext::makeCurrent: eglError: %x, this: %p \n", err, this);
+        }
     }
 
     return ok;
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 5d94ec3c38..5dfc48df99 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -2294,6 +2294,14 @@ void *QWindowsWindow::surface(void *nativeConfig)
 #endif
 }
 
+void QWindowsWindow::invalidateSurface()
+{
+    if (m_surface) {
+        m_data.staticOpenGLContext->destroyWindowSurface(m_surface);
+        m_surface = 0;
+    }
+}
+
 void QWindowsWindow::setTouchWindowTouchTypeStatic(QWindow *window, QWindowsWindowFunctions::TouchWindowTouchTypes touchTypes)
 {
     if (!window->handle())
diff --git a/src/plugins/platforms/windows/qwindowswindow.h b/src/plugins/platforms/windows/qwindowswindow.h
index 66102511e0..3e2f488f46 100644
--- a/src/plugins/platforms/windows/qwindowswindow.h
+++ b/src/plugins/platforms/windows/qwindowswindow.h
@@ -254,6 +254,7 @@ public:
     void setWindowIcon(const QIcon &icon);
 
     void *surface(void *nativeConfig);
+    void invalidateSurface() Q_DECL_OVERRIDE;
 
 #ifndef Q_OS_WINCE
     void setAlertState(bool enabled);