Possible buffer overrun with _FORTIFY_SOURCE.

[Mats Erik Andersson <debian@gisladisker.se>]

Hello there,

we are struggling with a segmentation fault arising on Wheezy
exactly when CPPFLAGS contains "-D_FORTIFY_SOURCE=2".

Looking at the fairly recent patch

  cvs-FORTIFY-SOURCE-format-strings.diff

I observe the new code

  args_type = &args_size[nargs];
  memset (args_type, ..., nargs * sizeof (*args_type));

You are initialising ARGS_TYPE to the very last element
of an array, yet you are setting memory content possibly
far beyond the end point of the very same array. Would not

  args_type = &args_size[0];

have been the correct statement? I am fumbling in the dark
as to our problem, but this seems to be a critical point.

Best regards,

  Mats Erik Andersson, DM