Log Message:
xapian-omega: update to 1.4.24. Changes:

documentation:

* Document $filesize error handling.

indexers:

* omindex:

  + Implement piped input to filters for __WIN32__.  Previously it looks like
    the filter was run but the input wasn't connected to its stdin so it would
    probably block indefinitely.

  + Fix corner case in shell emulation - we no longer set environment variables
    which start with a digit.

    This issue was spotted from reading the code - in practice this isn't a
    case that's likely to be encountered, and the previous behaviour doesn't
    appear to have any security consequences even if a user was somehow tricked
    into specifying an extraction command did this.

* scriptindex:

  + Check if we can actually support %z in parsedate action.  Previously we
    assumed we could if struct tm had a tm_gmtoff member, but that's only a
    necessary condition and not sufficient, e.g. on Cygwin we have tm_gmtoff
    but strptime() doesn't currently understand %z.

  + If we were expecting an action but didn't get an identifier this triggered
    an infinitely repeating error:

    Unknown index action ''

    Now we instead give a single error:

    Expected index action, found '...'

    where '...' shows the sequence of non-whitespace characters encountered.

testsuite:

* Run tests under eatmydata if available.

* Turn off MSYS2 argument conversion for tests as it breaks omegatest, and we
  shouldn't need this conversion there.

* omegatest: Rewrite in Perl as we were hitting non-portable quoting issues
  with the shell implementation, and really it had grown too large to make
  sense as a shell script anyway.

build system:

* Add --enable-werror configure option.

* configure: Only auto-enable -D_FORTIFY_SOURCE=2 if it works without
  additional libraries and remove the hard-coded block against using it
  on mingw.  Mingw-w64 v11.0.0 eliminated the requirement to link with -lssp
  so we now auto-enable -D_FORTIFY_SOURCE=2 there.

portability:

* Fix to build on Cygwin.

* Rename our bswap32 helper function to avoid clash with system-provided
  function on FreeBSD and NetBSD.