[Pkg-libburnia-devel] Bug#746254: xorriso: Sigbus on sparc when generating iso file.

[Thomas Schmitt]

Hi,

i can reproduce the SIGBUS only when gcc got option -O2.
(I removed all -O2 from ./configure, ran make clean and make.)

I can silence the error, with -O2 enabled, by replacing
        a->u = *(union w_list_data *)data;
with
        memcpy(&(a->u), data, sizeof(union w_list_data));

So this seems to be a bug of gcc, unless somebody can point
me to C prescriptions which would declare the "a->u =" variant
undefined or elsewise ambiguous.

I will test the error preventing code change in upstream now
and will apply it if no obstacles appear.
But we have to expect more such pitfalls if -O2 stays enabled
in the Debian compilation of libburn, libisofs, and libisoburn.

I really would had thought that -O2 was safe with gcc.
Now i have to reconsider.


I propose to try whether the strcmp() problem of genisoimage
in bug 731806 is related to -O2 too.


Currently i am waiting for Sebastien to provide me with the
input directory tree which on the first hand caused this bug
report. Just to be sure that no other bugs pester this use case.


Have a nice day :)

Thomas