Re: Internal regex.h is always used

[Paolo Bonzini]

On 09/17/2010 01:01 PM, Reuben Thomas wrote:
> So, you're saying that all the features in the gnulib version of GNU
> regex have been in glibc for sufficiently long that I am very unlikely
> ever to use a system with a sufficiently old version of glibc that it
> is lacking a feature (e.g. a particular syntax flag) that is present
> in GNU regex? Or that in this case, the gnulib tests will identify
> this problem and force --with-included-regex? If so, I agree, there is
> no real problem here (other than for me: I modified regex.h to add my
> RE_PLAIN, and then found that if I tested for RE_PLAIN I could still
> end up with the system library; however, this is, I agree, a rare
> case).

There is one case that comes to mind, which is REG_STARTEND (6-7 years 
old).  It's tested like this, which is not enough:

            /* REG_STARTEND was added to glibc on 2004-01-15.
               Reject older versions.  */
            if (! REG_STARTEND)
              return 1;

Paolo