qt6_windows7_patches

Patches that make qtbase 6.11.2 build and run on Windows 7, 8 and 8.1, and restore the ANGLE OpenGL ES / EGL backend Qt 6 dropped.

Applying

git clone https://github.com/desktop-app/qt6_windows7_patches.git qt6_windows7

win32_win64:
    for %%i in (..\..\qt6_windows7\*.patch) do (
        git apply %%i --ignore-whitespace -v
        if errorlevel 1 (
            echo ERROR: Applying patch %%~nxi failed!
            exit /b 1
        )
    )
win:
    for /r %%i in (..\..\patches\qtbase_%QT%\*) do (
        git apply %%i --ignore-whitespace -v
        ...
    )

This series first, qtbase_$QT on top.

The series

Cumulative, apply in order. 0001 is the upstream backport as it came, everything after it is a separate change on top. Nothing here duplicates qtbase_6.11.2 patches, they apply on top.

Patch	Files	What it is
0001	39	Windows 7 backport, from qr243vbi/qt6windows7
0002	1	DirectComposition on Windows 7 path, with FLIP_SEQUENTIAL
0003	1	6.11 notifyRoleChange UI Automation call routed through wrapper
0004	40	ANGLE OpenGL ES and EGL backend, from dimula73/qtbase for-krita/6.11.0, minus its env-gated resize experiments
0005	1	ANGLE entry points resolved statically, so libEGL.dll and libGLESv2.dll are not shipped
0006	1	Render-to-texture hole clipped to repainted region, also from Krita fork
0007	1	Opaque windows on blit (DISCARD) swap chain so Present never blocks, same as qtbase_6.11.2 change for stock path
0008	10	ANGLE device-loss and resource recovery ported from our Qt 5 patches
0009	2	GPU driver exclusions preserved when selecting ANGLE backends
0010	1	System DPI, metrics and font scaling preserved in legacy Windows shims
0011	1	ANGLE clear-surface resize and presentation failures propagated; normal flush is covered by common Qt patch 0064
0014	1	ANGLE clear-surface path rejects a failed swap-chain allocation

What it does

Qt 6 assumes Windows 10 APIs are always present; the series resolves them at runtime and falls back on Windows 7. Stock Qt 6 behaviour is kept on newer Windows.

DirectComposition is Windows 8+, so Windows 7 gets the plain swap chain path. QRhi over D3D11 also needs ID3D11DeviceContext1 from the Platform Update (KB2670838); without it Qt falls back to OpenGL, and ANGLE over Direct3D 9Ex covers drivers with no usable desktop OpenGL.

Moving to a new Qt version

tools/port_to_version.sh v6.11.2 v6.12.0

Re-merges every patched file against upstream and regenerates the series into <workdir>/out, one commit per patch. Review, then copy over. 6.11.1 to 6.11.2 cost one conflict in 12 touched files.

Line endings

LF everywhere, pinned by .gitattributes, because qtbase is LF. A CRLF checkout makes every file conflict during a port.