How to detect whether Windows 10 buffer wrapping m

Is there any way to detect whether a console app is running with Windows 10's new features enabled?

This MSDN page shows that HKEY_CURRENT_USER\Console\ForceV2, HKEY_CURRENT_USER\Console\LineWrap and HKEY_CURRENT_USER\Console\{name}\LineWrap control it, but besides that being less robust to parse, it may not be correct. If the user switches to or from legacy mode, the change won't take effect until the console relaunches.

If I develop the app, I can do the check at startup. There could have been a race condition though, which renders the registry check useless for any practical use. I am curious what the solution would be for third party console windows.

There seems to be no API for that, though I'd expect one to surface in some later SDK (maybe additional hyper-extended flags in GetConsoleMode).

Meanwhile, the following is a quick hack which attempts to detect the resize-wider capability of the new console, based on checking the ptMaxTrackSize.X value returned by GetMinMaxInfo.

The legacy console doesn't allow resizing the window wider than the screen buffer width, while the new one does. On the assumptions that (a) the console is running at full buffer width i.e. has no horizontal scrollbar, and (b) it's not already stretched to the full/max screen width, it's fairly straightforward to check whether the window allows itself to be resized wider (new console) or not (legacy console). Should be noted that assumption (a) could technically be avoided by manually converting the buffer width from characters to pixels, rather than relying on GetWindowRect, but assumption (b) is pretty much unavoidable.

This is the code (disclaimer: quick-and-dirty proof-of concept, no error checking etc).

int main()
{
    // largest possible console size for given font and desktop
    HANDLE hOut = GetStdHandle(STD_OUTPUT_HANDLE);
    COORD cd = GetLargestConsoleWindowSize(hOut);
    SHORT nScrMaxXch = cd.X, 
        nScrMaxYch = cd.Y;

    // current and max console sizes for given screen buffer
    CONSOLE_SCREEN_BUFFER_INFOEX csbix = { sizeof(csbix) };
    GetConsoleScreenBufferInfoEx(hOut, &csbix);
    SHORT nWndXch = csbix.srWindow.Right - csbix.srWindow.Left + 1,
        nWndYch = csbix.srWindow.Bottom - csbix.srWindow.Top + 1;
    SHORT nWndMaxXch = csbix.dwMaximumWindowSize.X,
        nWndMaxYch = csbix.dwMaximumWindowSize.Y;

    wprintf(L"chars:   wnd-size %d %d, max-wnd-size %d %d, largest-size %d %d\n",
        nWndXch, nWndYch, nWndMaxXch, nWndMaxYch, nScrMaxXch, nScrMaxYch);

    // current window size
    HWND hWnd = GetConsoleWindow();
    RECT rc; GetWindowRect(hWnd, &rc);
    LONG nWndXpx = rc.right - rc.left,
        nWndYpx = rc.bottom - rc.top;

    // max window tracking size
    MINMAXINFO mmi = { 0 };
    SendMessage(hWnd, WM_GETMINMAXINFO, 0, (LPARAM)&mmi);
    LONG nWndMaxXpx = mmi.ptMaxTrackSize.x,
        nWndMaxYpx = mmi.ptMaxTrackSize.y;

    wprintf(L"pixels:  wnd-size %lu %lu, max-tracking-size %lu %lu\n",
        nWndXpx, nWndYpx, nWndMaxXpx, nWndMaxYpx);

    if (nWndXch == nWndMaxXch   // full buffer width, no h-scrollbar 
    && nWndXch < nScrMaxXch     // not already stretched to full screen width
    && nWndMaxXpx > nWndXpx)    // allowed to resized wider
        wprintf(L"\n...most likely a Win10 console with ForceV2 enabled\n");

    return 0;
}

This is the output when run in a legacy console.

chars:   wnd-size 80 25, max-wnd-size 80 71, largest-size 240 71
pixels:  wnd-size 677 443, max-tracking-size 677 1179

This is the output when run in the new console.

chars:   wnd-size 80 25, max-wnd-size 80 71, largest-size 239 71
pixels:  wnd-size 677 443, max-tracking-size 1936 1186

...most likely a Win10 console with ForceV2 enabled