configure: Avoid PDF generation by default if don't have dblatex

Changed handling of --with-pdf-backend[=yes] to avoid picking the default
xmlto backend for PDF generation because it's broken.

The default xmlto backend for PDF generation can still be selected using
--with-pdf-backend=default if you really want to try it.

diff --git a/configure.ac b/configure.ac
index 428e07c5fd45117c6c126bb08a1c45fd7237dc80..97c848e55d5ff621305f3fc5c9a618ec11a5db2f 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -197,7 +197,15 @@ if test "$XMLTO" != "no"; then
                # Prefer dblatex, then default backend.
                # Could use [dblatex fop] to prefer dblatex or fop.
                AC_CHECK_PROGS([PDF_BACKEND], [dblatex], [default])
-               AC_MSG_NOTICE([Will use $PDF_BACKEND backend for PDF generation])
+               # The default backend is broken, so avoid it for now.
+               if test "$PDF_BACKEND" = "default"; then
+                       AC_MSG_WARN([Default PDF backend is broken, disabling PDF generation])
+                       AC_MSG_WARN([(dblatex is recommended for PDF generation)])
+                       PDF_BACKEND="no"
+               fi
+               if test "$PDF_BACKEND" != "no"; then
+                       AC_MSG_NOTICE([Will use $PDF_BACKEND backend for PDF generation])
+               fi
                ;;
        default)
                # Use xmlto's default backend.