Autoconf : Try to select the correct Qt tools by using the -qt option

With this change, it is now possible to configure with --enable-qt5
and have make use "moc -qt=qt5" automatically.

This is done when the command qtchooser is available nd the desired Qt
version (qt4/qt5) is available.

This means that it is now possible to have qt4 and qt5 builds easily
on a same linux system.

diff --git a/config/qt4.m4 b/config/qt4.m4
index 2bcd4f3bfc51bca53c990f572b5a9a702c842601..14390f8443e7dce0d14bfc9fb604bcdf5faf2f91 100644 (file)
--- a/config/qt4.m4
+++ b/config/qt4.m4
@@ -71,11 +71,17 @@ AC_DEFUN([QT_FIND_TOOL],
        if test "x$USE_QT5" != "xno" ; then
                qt_ext=qt5
        fi
+
+       lyx_qt_path=$PATH
        if test -n "$qt_cv_bin" ; then
-               AC_PATH_PROGS($1, [$2], [], $qt_cv_bin)
+               lyx_qt_path=$qt_cv_bin:$PATH
+       fi
+
+       if qtchooser -l 2>/dev/null | grep -q ^$qt_ext\$ >/dev/null ; then
+               AC_CHECK_PROG($1, $2, [$2 -qt=$qt_ext],, [$lyx_qt_path])
        fi
        if test -z "$$1"; then
-               AC_PATH_PROGS($1, [$2-$qt_ext $2],[],$PATH)
+               AC_CHECK_PROGS($1, [$2-$qt_ext $2],[],$lyx_qt_path)
        fi
        if test -z "$$1"; then
                AC_MSG_ERROR([cannot find $2 binary.])