[PATCH] Device init: Don't crash when CreateGC fails.

[Pierre-Loup A. Griffais]

That looks good to me. Sorry I for introducing this!
  - Pierre-Loup

On 05/14/2010 11:37 AM, Jamey Sharp wrote:
> ActivateDevice was ignoring errors from DeviceCursorInitialize, so
> cursor-related calls failed later. Jeremy Huddleston saw that crash in
> miPointerConstrainCursor, while with Xvfb I saw it in
> miSpriteRealizeCursor.
>
> miDCDeviceCleanup frees any non-NULL GCs. miDCDeviceInitialize calls
> Cleanup on any failure, but if it failed early then some of the pointers
> in the miDCBufferPtr were garbage. Switch from malloc to calloc to
> ensure everything's initialized safely first.
>
> With these two fixes, if CreateGC fails then the server gracefully fails
> in FatalError instead of segfaulting.
>
> Signed-off-by: Jamey Sharp<jamey at minilop.net>
> Cc: Peter Hutterer<peter.hutterer at who-t.net>
> ---
>   dix/devices.c  |    3 ++-
>   mi/midispcur.c |    2 +-
>   2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/dix/devices.c b/dix/devices.c
> index de72c88..5bffcac 100644
> --- a/dix/devices.c
> +++ b/dix/devices.c
> @@ -467,7 +467,8 @@ ActivateDevice(DeviceIntPtr dev, BOOL sendevent)
>
>       /* Initialize memory for sprites. */
>       if (IsMaster(dev)&&  dev->spriteInfo->spriteOwner)
> -        pScreen->DeviceCursorInitialize(dev, pScreen);
> +        if (!pScreen->DeviceCursorInitialize(dev, pScreen))
> +	    return BadImplementation;
>
>       SendDevicePresenceEvent(dev->id, DeviceAdded);
>       if (sendevent)
> diff --git a/mi/midispcur.c b/mi/midispcur.c
> index 1acc469..4de37d7 100644
> --- a/mi/midispcur.c
> +++ b/mi/midispcur.c
> @@ -780,7 +780,7 @@ miDCDeviceInitialize(DeviceIntPtr pDev, ScreenPtr pScreen)
>       {
>           pScreen = screenInfo.screens[i];
>
> -        pBuffer = malloc(sizeof(miDCBufferRec));
> +        pBuffer = calloc(1, sizeof(miDCBufferRec));
>           if (!pBuffer)
>               goto failure;
>