[BRLTTY] BRLTTY 4.4 segfault with backtrace

[Jason White]

Samuel Thibault <samuel.thibault at ens-lyon.org> wrote:
 
> Could you try this one?

With this patch applied, we still segfault at the same line, with disp ==
NULL.

Interestingly, this bug was hard to trigger under BRLTTY 4.3, but under 4.4 I
am finding that I can reliably reproduce it - I just power down the braille
display, ask another user to log into the machine and start an X session -
that's enough to cause a segfault at some point soon after.

I also have suspicions about the last few lines of te log that I sent to Dave:

1. The log reports the Baum display power down.

2. It then receives an API command and starts probing all of the drivers. The
Baum driver is not activated (because the display is connected but
unavailable). We then see this (starting with the last driver tested):


2012-06-16 at 16:21:20.385 braille driver initialization failed: vo -> usb:
2012-06-16 at 16:21:20.385 braille driver not found
2012-06-16 at 16:21:20.385 Braille Display Dimensions: 1 row, 80 columns
2012-06-16 at 16:21:20.385 regions: text=0.80 status=0.0
2012-06-16 at 16:21:20.385 shifts: full=80 half=40 vertical=5
2012-06-16 at 16:21:22.262 Received Write request on fd 5
2012-06-16 at 16:21:22.262 charset UTF-8

then there's a segfault as confirmed in the kernel logs and the core file.

Let me know how I can help further with the debugging.