Windows: Set opengl swap interval whenever we make a new window current

Apparently the windows OpenGL implementation associates the swap interval
not with the context, but with the window.

Fixes: QTBUG-59660
Change-Id: I78c4cc9f8a5815779a7489edfd731a1debb1e590
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/plugins/platforms/windows/qwindowsglcontext.cpp b/src/plugins/platforms/windows/qwindowsglcontext.cpp
index 851a6c961e..21cb794196 100644
--- a/src/plugins/platforms/windows/qwindowsglcontext.cpp
+++ b/src/plugins/platforms/windows/qwindowsglcontext.cpp
@@ -1350,10 +1350,10 @@ bool QWindowsGLContext::makeCurrent(QPlatformSurface *surface)
     // Set the swap interval
     if (m_staticContext->wglSwapInternalExt) {
         const int interval = surface->format().swapInterval();
-        if (interval >= 0 && m_swapInterval != interval) {
+        if (m_swapInterval != interval)
             m_swapInterval = interval;
+        if (interval >= 0)
             m_staticContext->wglSwapInternalExt(interval);
-        }
     }
 
     return success;