I fully agree that there is a faulty misleading outer size report.
What i checked however is that using dwStyleEx = 0, strangely produce the correct client area size, just like when using AdjustWindowRectEx.
But the size reported by GetWindowRect is still wrong, when compared to the pixel size of a screen capture of the window done in PhotoShop.
Be aware also that in Windows 10, the border of a resizable window or a fixed one, are now looking always the same.
Only one single pixel line, with no more grip on the bottom right corner in case of resizable window.
Thus things have changed, and especially for those who are not using the AdjustWindowRectEx before using CreateWindowEx with a popup window.
The only way to have a consistent appearence with all OS, is to use a Skin Engine.
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