xapian-bindings/configure.ac: project_version needs to be properly delimited

[Anthony G. Basile]

Using autoconf 2.69 on Gentoo, we hit the follow configure error i we autoreconf configure.ac.

checking for xapian-config-1.3... no
configure: error: Can't find xapian-config, although the xapian-core runtime library seems to be installed.  If you've installed xapian-core from a package, you probably need to install an extra package called something like xapian-core-devel in order to be able to build code using the Xapian library.

This is because project_version is not properly delimited with [...] on line 93 and this messes up the regex. The fix is trivial.

This is a problem in 1.3.4 and git/HEAD.

[Olly Betts]

project_version is intended to be substituted there by m4, so it's correct that it isn't quoted.

So thanks for reporting, but this isn't a bug - it's an intentional fix for a bug in earlier versions:

• configure script now defaults to looking for xapian-config-1.3. This is now automatically done for development series (odd middle component of the version number), but not for stable series (even middle component). Fixes #695, reported by Jorge C. Leitão

If you actually want the previous behaviour, specify XAPIAN_CONFIG explicitly, which will work for 1.3.4 and older versions:

./configure XAPIAN_CONFIG=xapian-config