Bug in Glibc Regex

[Andreas Pour <pour at mieterra dot com>]

Hi,

I just installed glibc 2.1.3 to run with php, and was disappointed to
find that a lot of my scripts were broken.

In glibc 2.1.1 and 2.1.2, and just about any other regex I have ever
used, the phrase "{text}" worked as a regex.  Now it doesn't, treating
the '{' as a bound counter delimiter.  My understanding was that '{'
should act that way only if followed by an integer, as the test case is
not.  It's obviously not a count delimiter, and regex never thought so
before.  From man 7 regex:

       A bound is `{' followed by an  unsigned  decimal  integer,
       possibly  followed  by  `,'  possibly  followed by another
       unsigned decimal integer, always  followed  by  `}'.   The
       integers  must  lie  between 0 and RE_DUP_MAX (255) inclu­
       sive, and if there are two of  them,  the  first  may  not
       exceed the second.  An atom followed by a bound containing
       one integer i and no comma matches a sequence of exactly i
       matches of the atom.  An atom followed by a bound contain­
       ing one integer i and a comma matches a sequence of  i  or
       more  matches  of  the  atom.  An atom followed by a bound
       containing two integers i and j matches a  sequence  of  i
       through j (inclusive) matches of the atom.

I realize this statement does not explicitly say that an occurrence of
'{' w/out a following integer does not have to be escaped, but it
certainly implies it; e.g. the definition of the metacharacter '[' does
not specify that any special character has to follow it to have a
special meaning.  I don't have POSIX 1003.2 handy and IEEE makes it hard
to come by.  My suspicion is that this change does not comply with
POSIX 1003.2?

The attached file outputs:

  Matches:
          Position 11 - 17

on glibc-2.1.1 and

  Compilation of regex '{test}' failed, error 'Invalid content of \{\}'.

on glibc-2.1.3.

Switching to using "const char *text = '\\{test\\}'" works on both
versions of glibc.

Ciao,

Andreas Pour