• Adam Jackson's avatar
    glx: Lift sending the MakeCurrent request to top-level code · 80b67a3b
    Adam Jackson authored
    Somewhat terrifyingly, we never sent this for direct contexts, which
    means the server never knew the context/drawable bindings. To handle
    this sanely, pull the request code up out of the indirect backend, and
    rewrite the context switch path to call it as appropriate.  This
    attempts to preserve the existing behavior of not calling unbind() on
    the context if its refcount would not drop to zero.
    Of course, you can't just do this indiscriminately, because this is GLX
    and extant X servers have bugs and everything is terrible. To wit:
    - For 1.20.x prior to 1.20.6, you can bind a direct context once, but
    the second time you try to modify the context's binding you will get
    GLXBadContextTag. This includes unbinding the context. And "deleting"
    the context will leak memory, because it will still appear to be
    - For 1.19 and earlier, glXMakeCurrent(dpy, None, ctx) should be legal
    for GL 3.0+ contexts, but the server will throw BadMatch.
    To guard against this, we only send the request for indirect contexts
    unless the server is known good, and only mention one context at a time
    in such a request; if switching between contexts, we first unbind the
    old, and then bind the new. Note that the second VendorRelease() version
    is to catch XFree86 4.x and Xorg [67].x, which almost certainly have the
    above bugs. Other servers might report different version numbers here,
    but we can't do direct rendering against them, so this should be safe.
    Fixes: mesa/mesa#4418
    Acked-By: Mike Blumenkrantz's avatarMike Blumenkrantz <michael.blumenkrantz@gmail.com>
    Part-of: <mesa/mesa!9992>
piglit-v3d-rpi4-fails.txt 6.73 KB