Re: locale-related printf bug when using formats with thousands grouping character

[Bruno Haible]

The bug affects not only %f but also %g, and it can lead to a SIGSEGV.

Reproduce with the bash 3.2.1 built-in:

$ LC_ALL=en_US.UTF-8 bash -c "printf \"%'.5g\\\\n\" 999.996"
1000
$ LC_ALL=en_US.UTF-8 bash -c "printf \"%'.4g\\\\n\" 9999.996"
Segmentation fault
$ LC_ALL=en_US.UTF-8 bash -c "printf \"%'.5g\\\\n\" 99999.996"
Segmentation fault
$ LC_ALL=en_US.UTF-8 bash -c "printf \"%'.6g\\\\n\" 999999.996"
Segmentation fault
$ LC_ALL=en_US.UTF-8 bash -c "printf \"%'.7g\\\\n\" 9999999.996"
Segmentation fault

or with the printf program from coreutils 8.4:

$ env LC_ALL=en_US.UTF-8 printf "%'.5g\\n" 999.996
1000
$ env LC_ALL=en_US.UTF-8 printf "%'.4g\\n" 9999.996
Segmentation fault
$ env LC_ALL=en_US.UTF-8 printf "%'.5g\\n" 99999.996
Segmentation fault
$ env LC_ALL=en_US.UTF-8 printf "%'.6g\\n" 999999.996
Segmentation fault
$ env LC_ALL=en_US.UTF-8 printf "%'.7g\\n" 9999999.996
Segmentation fault

I've added a second test program to your bug report at
<http://sourceware.org/bugzilla/show_bug.cgi?id=12394>.

Bruno

#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int
main ()
{
  char buf1[1000];
  char buf2[1000];
  int result = 0;

  if (setlocale (LC_NUMERIC, "en_US.UTF-8") == NULL)
    return 1;

  sprintf (buf1, "%'.2f",  999.996);
  sprintf (buf2, "%'.2f", 1000.004);
  if (strcmp (buf1, buf2) != 0)
    result |= 2;

  sprintf (buf1, "%'.2f",  999999.996);
  sprintf (buf2, "%'.2f", 1000000.004);
  if (strcmp (buf1, buf2) != 0)
    result |= 2;

  sprintf (buf1, "%'.2f",  999999999.996);
  sprintf (buf2, "%'.2f", 1000000000.004);
  if (strcmp (buf1, buf2) != 0)
    result |= 2;

  sprintf (buf1, "%'.2f",  999999999999.996);
  sprintf (buf2, "%'.2f", 1000000000000.004);
  if (strcmp (buf1, buf2) != 0)
    result |= 2;

  sprintf (buf1, "%'.2f",  999999999999999.996);
  sprintf (buf2, "%'.2f", 1000000000000000.004);
  if (strcmp (buf1, buf2) != 0)
    result |= 2;

  sprintf (buf1, "%'.5g",  999.996);
  sprintf (buf2, "%'.5g", 1000.004);
  if (strcmp (buf1, buf2) != 0)
    result |= 4;

  sprintf (buf1, "%'.4g",  9999.996);
  sprintf (buf2, "%'.4g", 10000.004);
  if (strcmp (buf1, buf2) != 0)
    result |= 8;

  sprintf (buf1, "%'.5g",  99999.996);
  sprintf (buf2, "%'.5g", 100000.004);
  if (strcmp (buf1, buf2) != 0)
    result |= 8;

  sprintf (buf1, "%'.6g",  999999.996);
  sprintf (buf2, "%'.6g", 1000000.004);
  if (strcmp (buf1, buf2) != 0)
    result |= 8;

  sprintf (buf1, "%'.7g",  9999999.996);
  sprintf (buf2, "%'.7g", 10000000.004);
  if (strcmp (buf1, buf2) != 0)
    result |= 8;

  return result;
}