[Mesa-dev] [Mesa-stable] [PATCH 4/4] glx: fix error code when there is no context bound

[Tapani Pälli]

On 02/12/2016 11:55 PM, Emil Velikov wrote:
> On 12 February 2016 at 05:34, Tapani Pälli <tapani.palli at intel.com> wrote:
>> On 02/12/2016 02:54 AM, Emil Velikov wrote:
>>> On 11 February 2016 at 12:04, Tapani Pälli <tapani.palli at intel.com> wrote:
>>>> From: Bernard Kilarski <bernard.r.kilarski at intel.com>
>>>>
>>>> Signed-off-by: Bernard Kilarski <bernard.r.kilarski at intel.com>
>>>> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
>>>> Cc: "11.0 11.1" <mesa-stable at lists.freedesktop.org
>>>> ---
>>>>    src/glx/glxcmds.c                         | 2 +-
>>>>    src/glx/query_renderer.c                  | 4 ++--
>>>>    src/glx/tests/query_renderer_unittest.cpp | 4 ++++
>>>>    3 files changed, 7 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/src/glx/glxcmds.c b/src/glx/glxcmds.c
>>>> index 93e8db5..4db67ec 100644
>>>> --- a/src/glx/glxcmds.c
>>>> +++ b/src/glx/glxcmds.c
>>>> @@ -1727,7 +1727,7 @@ __glXSwapIntervalSGI(int interval)
>>>>       CARD32 *interval_ptr;
>>>>       CARD8 opcode;
>>>>
>>>> -   if (gc == NULL) {
>>>> +   if (gc == NULL || gc == &dummyContext) {
>>>>          return GLX_BAD_CONTEXT;
>>>>       }
>>>>
>>>> diff --git a/src/glx/query_renderer.c b/src/glx/query_renderer.c
>>>> index 9108ec2..d49b8fe 100644
>>>> --- a/src/glx/query_renderer.c
>>>> +++ b/src/glx/query_renderer.c
>>>> @@ -106,7 +106,7 @@ glXQueryCurrentRendererIntegerMESA(int attribute,
>>>> unsigned int *value)
>>>>    {
>>>>       struct glx_context *gc = __glXGetCurrentContext();
>>>>
>>>> -   if (gc == NULL)
>>>> +   if (gc == NULL || gc == &dummyContext)
>>>>          return False;
>>>>
>>>>       return __glXQueryRendererInteger(gc->psc, attribute, value);
>>>> @@ -166,7 +166,7 @@ glXQueryCurrentRendererStringMESA(int attribute)
>>>>    {
>>>>       struct glx_context *gc = __glXGetCurrentContext();
>>>>
>>>> -   if (gc == NULL)
>>>> +   if (gc == NULL || gc == &dummyContext)
>>> Unless I'm missing something __glXGetCurrentContext() can never return
>>> NULL, right ?
>>
>> This was my initial impression also ... but I'm not sure what happens here
>> but unit tests (glx-test) for some reason completely explode if you take out
>> the null check and try running 'make check'.
>>
>> I think that is why also the dummyContext is introduced in those tests. I
>> played around a bit with this change and linking phase with glx-test starts
>> to print quite weird errors, actually complete unrelated ones, I guess
>> because it cannot find the 'extern' declared 'dummyContext'. I'm not sure if
>> this is actually problem with the tests rather than this code.
>>
> Double checking - the tests are going crazy when you remove the null
> check, even with the current/extra dummyContext ? That does sound
> quite strange.

Yep that's the case.

// Tapani