[Mesa-dev] Request to revert commit [3d81e11b49366b5636b8524ba0f8c7076e3fdf34] mesa: remove, unnecessary, 'sort by year' for the GL extensions

[Roland Scheidegger]

Am 20.09.2018 um 15:09 schrieb Ian Romanick:
> On 09/19/2018 11:36 PM, Federico Dossena wrote:
>> As most of you are probably aware of, id2 and id3 games store GL
>> extensions in a buffer that's too small for modern systems. This usually
>> leads to a crash when MESA_EXTENSION_MAX_YEAR is not set, but what the
>> creator of this commit didn't know is that some id3 games (the more
>> "recent" ones) don't crash, they just truncate the string. As a result
>> of this commit, these games can't detect some extensions and therefore
>> don't work properly.
> 
> It sounds like the problem is still that MESA_EXTENSION_MAX_YEAR is not
> set, so why not just set it?  Doesn't that fix the problem?
Yes it does.
It is however not really obvious why an app is failing (in this case the
game still ran, just shadows were broken - I suppose they were not
tested without some extensions being available).
I suppose we could try detecting affected apps by name, but I have no
idea which are (possibly some later published games using id tech 3 have
it fixed for real, I have no idea).
It is not a mesa specific problem neither, since apparently windows AMD
drivers suffer from the same issue. Maybe nvidia always reorders
extensions (or recognizes affected apps).

Roland


> 
>> I discovered this while trying to figure out why dynamic lights in Star
>> Trek Voyager Elite Force (2000) suddenly broke with Mesa 18. I discussed
>> this with Ronald Scheidegger, who's been very helpful and helped me
>> figure out what was going on.
>>
>> Personally, I see nothing wrong with reverting this commit and keeping
>> the extensions sorted by year, it doesn't impact performance and it
>> doesn't break anything modern. What do you think about it?
>>
>