fftools/ffmpeg_mux_init: Fix attachment_filename use-after-free

The filename is freed with the OptionsContext and therefore
there will be a use-after-free when reporting the filename
in print_stream_maps(). So create a copy of the string.

This is a regression since 8aed3911fc454e79697e183660bf30d31334a64b.
fate-lavf-mkv_attachment exhibits it (and reports a random nonsense
filename here), but this does not make the test fail (not even with
valgrind; only with ASAN, as it aborts on use-after-free).

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

0 files changed, 0 insertions, 0 deletions