bug#31900: typo in libtool.m4 file (wrong -L/-R detection)

[Igor Rondarev]

Dear libtool maintenance team!

Please note that m4/libtool.m4 file (starting from 2.4.2.418) has incorrect string comparition that leads to wrong behaviour related to default library paths.

See m4/libtool.m4 at string 7559 (http://git.savannah.gnu.org/cgit/libtool.git/tree/m4/libtool.m4#n7559)

# Some compilers place space between "-{L,R}" and the path.
       # Remove the space.
       if test x-L = "$p" ||
          test x-R = "$p"; then
	 prev=$p
	 continue

Both tests are being performed without 'x' in right parts (i.e. "$p" instead of "x$p"), what makes them always false.

Hope this information is helpful.

Best regards,

Igor.