4 files changed, 40 insertions, 8 deletions
diff --git a/src/plugins/platforms/windows/qwindowsglcontext.cpp b/src/plugins/platforms/windows/qwindowsglcontext.cpp
index d63149e4ce..281f54a9d9 100644
--- a/src/plugins/platforms/windows/qwindowsglcontext.cpp
+++ b/src/plugins/platforms/windows/qwindowsglcontext.cpp
@@ -586,15 +586,17 @@ static HGLRC createContext(const QOpenGLStaticContext &staticContext,
         attributes[attribIndex++] = WGL_CONTEXT_MINOR_VERSION_ARB;
         attributes[attribIndex++] = minorVersion;
     }
+
+    int flags = 0;
+    if (format.testOption(QSurfaceFormat::DebugContext))
+        flags |= WGL_CONTEXT_DEBUG_BIT_ARB;
     if (requestedVersion >= 0x0300) {
-        attributes[attribIndex++] = WGL_CONTEXT_FLAGS_ARB;
-        attributes[attribIndex] = 0;
         if (!format.testOption(QSurfaceFormat::DeprecatedFunctions))
-             attributes[attribIndex] |= WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
-        if (format.testOption(QSurfaceFormat::DebugContext))
-            attributes[attribIndex] |= WGL_CONTEXT_DEBUG_BIT_ARB;
-        attribIndex++;
+            flags |= WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB;
     }
+    attributes[attribIndex++] = WGL_CONTEXT_FLAGS_ARB;
+    attributes[attribIndex++] = flags;
+
     if (requestedVersion >= 0x0302) {
         switch (format.profile()) {
         case QSurfaceFormat::NoProfile:
diff --git a/src/plugins/platforms/windows/qwindowstheme.cpp b/src/plugins/platforms/windows/qwindowstheme.cpp
index eb1bbd1ab0..00a5da8f44 100644
--- a/src/plugins/platforms/windows/qwindowstheme.cpp
+++ b/src/plugins/platforms/windows/qwindowstheme.cpp
@@ -383,6 +383,8 @@ QVariant QWindowsTheme::themeHint(ThemeHint hint) const
     }
     case DialogSnapToDefaultButton:
         return QVariant(booleanSystemParametersInfo(SPI_GETSNAPTODEFBUTTON, false));
+    case ContextMenuOnMouseRelease:
+        return QVariant(true);
     default:
         break;
     }
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 006a2802c1..d1d50eee73 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -1170,8 +1170,13 @@ void QWindowsWindow::show_sys() const
     if (type == Qt::Popup || type == Qt::ToolTip || type == Qt::Tool)
         sm = SW_SHOWNOACTIVATE;
 
+    if (w->windowState() & Qt::WindowMaximized)
+        setFlag(WithinMaximize); // QTBUG-8361
+
     ShowWindow(m_data.hwnd, sm);
 
+    clearFlag(WithinMaximize);
+
     if (fakedMaximize) {
         setStyle(style() & ~WS_MAXIMIZEBOX);
         SetWindowPos(m_data.hwnd, 0, 0, 0, 0, 0,
@@ -1582,8 +1587,11 @@ void QWindowsWindow::setWindowState_sys(Qt::WindowState newState)
     setFlag(FrameDirty);
 
     if ((oldState == Qt::WindowMaximized) != (newState == Qt::WindowMaximized)) {
-        if (visible && !(newState == Qt::WindowMinimized))
+        if (visible && !(newState == Qt::WindowMinimized)) {
+            setFlag(WithinMaximize);
             ShowWindow(m_data.hwnd, (newState == Qt::WindowMaximized) ? SW_MAXIMIZE : SW_SHOWNOACTIVATE);
+            clearFlag(WithinMaximize);
+        }
     }
 
     if ((oldState == Qt::WindowFullScreen) != (newState == Qt::WindowFullScreen)) {
@@ -1903,6 +1911,25 @@ void QWindowsWindow::getSizeHints(MINMAXINFO *mmi) const
 {
     const QWindowsGeometryHint hint(window(), m_data.customMargins);
     hint.applyToMinMaxInfo(m_data.hwnd, mmi);
+
+    if ((testFlag(WithinMaximize) || (window()->windowState() == Qt::WindowMinimized))
+            && (m_data.flags & Qt::FramelessWindowHint)) {
+        // This block fixes QTBUG-8361: Frameless windows shouldn't cover the
+        // taskbar when maximized
+        if (const QScreen *screen = effectiveScreen(window())) {
+            mmi->ptMaxSize.y = screen->availableGeometry().height();
+
+            // Width, because you can have the taskbar on the sides too.
+            mmi->ptMaxSize.x = screen->availableGeometry().width();
+
+            // If you have the taskbar on top, or on the left you don't want it at (0,0):
+            mmi->ptMaxPosition.x = screen->availableGeometry().x();
+            mmi->ptMaxPosition.y = screen->availableGeometry().y();
+        } else {
+            qWarning() << "Invalid screen";
+        }
+    }
+
     if (QWindowsContext::verboseWindows)
         qDebug() << __FUNCTION__ << window() << *mmi;
 }
diff --git a/src/plugins/platforms/windows/qwindowswindow.h b/src/plugins/platforms/windows/qwindowswindow.h
index f055864482..61dc3e2dc2 100644
--- a/src/plugins/platforms/windows/qwindowswindow.h
+++ b/src/plugins/platforms/windows/qwindowswindow.h
@@ -136,7 +136,8 @@ public:
         TouchRegistered = 0x4000,
         AlertState = 0x8000,
         Exposed = 0x10000,
-        WithinCreate = 0x20000
+        WithinCreate = 0x20000,
+        WithinMaximize = 0x40000
     };
 
     struct WindowData