Bug#617409: brasero: Brasero corrupts all blank CD-R when burning (was: additional info)

[Thomas Schmitt]

Hi,

i am currently the developer of libburn and libisofs.

> https://bugzilla.gnome.org/show_bug.cgi?id=655601

I know about such problems, but i do not know how to get into a
discussion with Brasero developers.
My impression is that the libisofs plugin causes libisofs to end
prematurely. libburn is less of a suspect here.


I have seen burn logs where burning ends after about 50 % of
the expected output was produced by libisofs. I.e. libisofs would
want to write more, but for some reason libburn is urged to finish
burning (or falsely decides that burning is done).
  https://bugs.launchpad.net/ubuntu/+source/brasero/+bug/780117
  https://launchpadlibrarian.net/71440716/brasero_log.txt
have:
> BraseroLibisofs Finished track successfully
> BraseroLibisofs disconnecting BraseroLibisofs from BraseroGrowisofs
> ...
> BraseroGrowisofs stdout:  3866984448/7761410048 (49.8%) @4.0x, remaining 12:06 RBU  40.9% UBU 100.0%
> BraseroGrowisofs called brasero_job_get_action
> BraseroGrowisofs called brasero_job_set_current_action
> BraseroGrowisofs stderr: /dev/sr0: flushing cache
> ...
> BraseroGrowisofs stderr: HUP

Note that libburn is not involved here. Only libisofs. Burning is done
via growisofs.
Further it seems that BraseroLibisofs is the one which decides when
the connection between both shall end.


But in
  http://bugzilla-attachments.gnome.org/attachment.cgi?id=205344
the work of libisofs seems to get completed.
> brasero (libisofs)DEBUG : Processed 138390 of 138390 KB (100 %)

So this might be two different problems.
(In this run, libburn was indeed in charge of writing to media.)


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I am not aware of any changes in libisofs or libburn which about a year
ago could have introduced such problems.
The combination of libisofs and libburn works fine in xorriso.
xorriso does several backups per day for me, which then get thoroughly
checked for readability and correct content.

If somebody shows up who understands the code of the libisofs plugin
and could make experiments, then i would be glad to help with finding
the cause of the problem.


Have a nice day :)

Thomas