Bad regex matcher

[Andreas Schwab]

The following program apparently runs into an infinite loop in the regex
matcher (from the grep testsuite):

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

#define PATTERN "^(.?)(.?)(.?)(.?)(.?)(.?)(.?)(.?)(.?).?\\9\\8\\7\\6\\5\\4\\3\\2\\1$"

int
main ()
{
  static struct re_pattern_buffer regex;
  const char *s;
  re_set_syntax (RE_SYNTAX_POSIX_EGREP);

  s = re_compile_pattern (PATTERN, strlen (PATTERN), &regex);
  if (s)
    exit (1);

  re_search (&regex, "civic", 5, 0, 5, 0);

  exit (0);
}

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux AG, Deutschherrnstr. 15-19, D-90429 Nürnberg
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