[RFC wayland 1/9] wayland-egl: import libwayland-egl.so frontend library from Mesa

[Emil Velikov]

On 19 September 2017 at 05:34, Duncan Roe <duncan_roe at optusnet.com.au> wrote:
> Hi Emil,
>
> On Mon, Sep 18, 2017 at 02:18:42PM +0100, Emil Velikov wrote:
>> Hi Duncan,
>>
>> On 17 September 2017 at 09:04, Duncan Roe <duncan_roe at optusnet.com.au> wrote:
>> > On Fri, Sep 15, 2017 at 11:29:19AM +0100, Emil Velikov wrote:
>> >> From: Emil Velikov <emil.velikov at collabora.com>
> ...
>>
>> > I've made the updates locally, and see that it still builds
>> > libwayland-egl.so.1.0.0. Shouldn't there be a version bump?
>> >
>> There is no difference in the sources or binary. Thus a version bump
>> is a very bad idea.
>>
> Perhaps I didn't explain properly:
>
> I built wayland-egl from code in Mesa-17.0.4. That built
> libwayland-egl.so.1.0.0. I rebuilt wayland-egl from your code in Mesa-17.1.9.
> That also built libwayland-egl.so.1.0.0.
>
> Between the 2 revisions, the layout of struct wl_egl_window is changed to have
> const intptr_t version inserted as its first element with struct wl_surface
> *surface moved from first element to last.
>
> The new .so builds to be the same size as the old one but cmp -l shows 1395
> differing bytes,
>
That's correct, yet the change is orthogonal to the import.

Even then this is a backend change, while a version bump indicates
frontend changes.
On the backend side one can easily detect the version at runtime see [1].

HTH
Emil

[1] https://cgit.freedesktop.org/mesa/mesa/log/?qt=author&q=miguel