Bug#869135: Please consider switching to giza

[Ole Streicher]

Hi again,

I think I got the problem: The segfault with debug symbols enabled is
when giza_print_id() calls strcat():

#0  __strcat_sse2_unaligned () at
../sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S:807
#1  0x00007fc420eb6f45 in giza_print_id () at giza-print-id.c:86
#2  0x00007fc42130eee5 in cpgiden () at giza-cpgplot.c:408
#3  0x00007fc42151de04 in XS_PGPLOT_pgiden (my_perl=<optimized out>,
cv=0x55b16a4e4820)
    at PGPLOT.xs:493
#4  0x000055b169c171b0 in Perl_pp_entersub ()
#5  0x000055b169c0f6f6 in Perl_runops_standard ()
#6  0x000055b169b95789 in perl_run ()
#7  0x000055b169b6e93d in main ()

And when looking into the giza source, it is clear what happens:

void giza_print_id (void) {
// ...
  /* get user id */
  char *userid = getlogin();
  if (userid == NULL) userid = "";

  /* get current date and time */
  struct tm *current;
  time_t now;
  time(&now);
  current = localtime(&now);

  /* format the date and time into a string */
  char date[20];
  strftime(date,sizeof(date)," %e-%h-%Y %H:%M",current);
  char *string = strcat(userid,date);
// ...

the strcat tries to append something to either the string returned by
getlogin(), or to the string constant "".

Both is wrong.

--> this is clearly a bug in giza; I will contact upstream with the
problem. However, this is probably easy to fix and should not be a
show-stopper. If you like, you can create a bug for giza to track the
progress.

Best regards

Ole