[PATCH] dix: Fill in errorValue in ChangeGC for tile/stipple/clip BadMatch

[Adam Jackson]

On 6/20/11 6:18 PM, Peter Hutterer wrote:
> On Sat, Jun 18, 2011 at 09:25:48AM +0200, Keith Packard wrote:
>> On Fri, 17 Jun 2011 15:26:41 -0400, Adam Jackson<ajax at redhat.com>  wrote:
>>
>>> +		    if (client)
>>> +			client->errorValue = pPixmap->drawable.id;
>>>   		    error = BadMatch;
>>
>> Oddly enough, a Match error does not return the mis-matching value.
>
> why not? can we change it? why not start doing so?

The protocol spec simply says "Other core errors return no additional 
data", where other happens to include BadMatch.

The caveat here is that unused data in errors isn't guaranteed to be 0, 
which means you'd have to know to only look for extra BadMatch info for 
either a particular server version or (better) protocol version.  You 
could reasonably make that part of protocol 11.1, on the assumption that 
11.0 clients wouldn't bother looking for it, but that 11.1 clients would 
want to be assured of it.

- ajax