3 files changed, 25 insertions, 19 deletions

diff --git a/src/plugins/platforms/windows/qwindowsglcontext.cpp b/src/plugins/platforms/windows/qwindowsglcontext.cpp
index 6fa5a8a2b3..1f49f0aefd 100644
--- a/src/plugins/platforms/windows/qwindowsglcontext.cpp
+++ b/src/plugins/platforms/windows/qwindowsglcontext.cpp
@@ -48,6 +48,7 @@
 #include <qpa/qplatformnativeinterface.h>
 #include <QtPlatformHeaders/qwglnativecontext.h>
 
+#include <private/qsystemlibrary_p.h>
 #include <algorithm>
 
 #include <wingdi.h>
@@ -162,19 +163,25 @@ QFunctionPointer QWindowsOpengl32DLL::resolve(const char *name)
 
 bool QWindowsOpengl32DLL::init(bool softwareRendering)
 {
-    const QByteArray opengl32 = QByteArrayLiteral("opengl32.dll");
-    const QByteArray swopengl = QByteArrayLiteral("opengl32sw.dll");
+    const QByteArray opengl32 = QByteArrayLiteral("opengl32");
+    const QByteArray swopengl = QByteArrayLiteral("opengl32sw");
+    bool useSystemLib = false;
 
     QByteArray openglDll = qgetenv("QT_OPENGL_DLL");
-    if (openglDll.isEmpty())
+    if (openglDll.isEmpty()) {
         openglDll = softwareRendering ? swopengl : opengl32;
+        useSystemLib = !softwareRendering;
+    }
 
     openglDll = openglDll.toLower();
     m_nonOpengl32 = openglDll != opengl32;
 
     qCDebug(lcQpaGl) << "Qt: Using WGL and OpenGL from" << openglDll;
 
-    m_lib = ::LoadLibraryA(openglDll.constData());
+    if (useSystemLib)
+        m_lib = QSystemLibrary::load((wchar_t*)(QString::fromLatin1(openglDll).utf16()));
+    else
+        m_lib = LoadLibraryA(openglDll.constData());
     if (!m_lib) {
         qErrnoWarning(::GetLastError(), "Failed to load %s", openglDll.constData());
         return false;
@@ -184,7 +191,7 @@ bool QWindowsOpengl32DLL::init(bool softwareRendering)
         // Load opengl32.dll always. GDI functions like ChoosePixelFormat do
         // GetModuleHandle for opengl32.dll and behave differently (and call back into
         // opengl32) when the module is present. This is fine for dummy contexts and windows.
-        ::LoadLibraryA("opengl32.dll");
+        QSystemLibrary::load(L"opengl32");
     }
 
     wglCreateContext = reinterpret_cast<HGLRC (WINAPI *)(HDC)>(resolve("wglCreateContext"));
diff --git a/src/plugins/platforms/windows/qwindowsopengltester.cpp b/src/plugins/platforms/windows/qwindowsopengltester.cpp
index d7d186e804..9eb4011bf2 100644
--- a/src/plugins/platforms/windows/qwindowsopengltester.cpp
+++ b/src/plugins/platforms/windows/qwindowsopengltester.cpp
@@ -49,6 +49,7 @@
 #include <QtCore/qstandardpaths.h>
 #include <QtCore/qlibraryinfo.h>
 #include <QtCore/qhash.h>
+#include <private/qsystemlibrary_p.h>
 
 #ifndef QT_NO_OPENGL
 #include <private/qopengl_p.h>
@@ -396,7 +397,7 @@ bool QWindowsOpenGLTester::testDesktopGL()
 
     // Test #1: Load opengl32.dll and try to resolve an OpenGL 2 function.
     // This will typically fail on systems that do not have a real OpenGL driver.
-    lib = LoadLibraryA("opengl32.dll");
+    lib = QSystemLibrary::load(L"opengl32");
     if (lib) {
         CreateContext = reinterpret_cast<CreateContextType>(
             reinterpret_cast<QFunctionPointer>(::GetProcAddress(lib, "wglCreateContext")));
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 3f7f925877..9820d1ec2c 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -2683,32 +2683,30 @@ void QWindowsWindow::getSizeHints(MINMAXINFO *mmi) const
 
     // This block fixes QTBUG-8361, QTBUG-4362: Frameless/title-less windows shouldn't cover the
     // taskbar when maximized
-    if ((testFlag(WithinMaximize) || window()->windowStates().testFlag(Qt::WindowMinimized))
-        && (m_data.flags.testFlag(Qt::FramelessWindowHint)
-            || (m_data.flags.testFlag(Qt::CustomizeWindowHint) && !m_data.flags.testFlag(Qt::WindowTitleHint)))) {
-        const QScreen *screen = window()->screen();
-
-        // Documentation of MINMAXINFO states that it will only work for the primary screen
-        if (screen && screen == QGuiApplication::primaryScreen()) {
-            const QRect availableGeometry = QHighDpi::toNativePixels(screen->availableGeometry(), screen);
+    if (m_data.flags.testFlag(Qt::FramelessWindowHint)
+        || (m_data.flags.testFlag(Qt::CustomizeWindowHint) && !m_data.flags.testFlag(Qt::WindowTitleHint))) {
+        if (QPlatformScreen *currentScreen = screen()) {
+            const QRect geometry = currentScreen->geometry();
+            const QRect availableGeometry = currentScreen->availableGeometry();
             mmi->ptMaxSize.y = availableGeometry.height();
 
             // Width, because you can have the taskbar on the sides too.
             mmi->ptMaxSize.x = availableGeometry.width();
 
             // If you have the taskbar on top, or on the left you don't want it at (0,0):
-            mmi->ptMaxPosition.x = availableGeometry.x();
-            mmi->ptMaxPosition.y = availableGeometry.y();
+            QPoint availablePositionDiff = geometry.topLeft() - availableGeometry.topLeft();
+            mmi->ptMaxPosition.x = availablePositionDiff.x();
+            mmi->ptMaxPosition.y = availablePositionDiff.y();
             if (!m_data.flags.testFlag(Qt::FramelessWindowHint)) {
-                const int borderWidth = getBorderWidth(screen->handle());
+                const int borderWidth = getBorderWidth(currentScreen);
                 mmi->ptMaxSize.x += borderWidth * 2;
                 mmi->ptMaxSize.y += borderWidth * 2;
                 mmi->ptMaxTrackSize = mmi->ptMaxSize;
                 mmi->ptMaxPosition.x -= borderWidth;
                 mmi->ptMaxPosition.y -= borderWidth;
             }
-        } else if (!screen){
-            qWarning("window()->screen() returned a null screen");
+        } else {
+            qWarning("screen() returned a null screen");
         }
     }