Re: [wxhaskell-users] Some WX questions - a couple of missing bindings and a segfault

[Jules B. <ju...@je...>]

Eric Kow wrote:
> Hi Jules,
> 
> Thanks for the test case.
> 
> It segfaults right away for me on Linux (iteration 0).  I don't even
> need the bitmap to make it do this; just
>    image <- imageCreateSized (WX.Size 256 256)
> 
> Also, I notice that it seems to happen Graphics.UI.WXCore.pixelBufferGetPixels
> 
> (This is via the old fashioned putStrLn style of debugging)
> 
> Do you confirm these?


Yes.

And what pixelBufferGetPixels does is peekCStringLen, which is 
essentially reading the entire buffer that image owns.

Whereas the other bug report you pointed me to read the image's buffer 
more gradually, but still hit the same error.

So somehow, sometimes, we're getting an invalid pointer. Whether it's a 
pointer to a buffer which is too short, or a buffer which has been 
moved, or....

Jules