Define datarootdir, docdir, htmldir and pdfdir if not defined by autoconf

(first defined in autoconf-2.59c).

diff --git a/configure.ac b/configure.ac
index 1acc52e7d913117d4e714475cd1d45d7f16cf4fa..bc9f62dad84ca503caeb8fdd7761cf12bbdfd994 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -48,6 +48,27 @@ COMEDILIB_LIBS="$COMEDILIB_LIBS \$(top_builddir)/lib/libcomedi.la -lm"
 AC_SUBST(COMEDILIB_CFLAGS)
 AC_SUBST(COMEDILIB_LIBS)
 
+# autoconf backwards compatibility
+if test "$datarootdir" = ""; then
+       datarootdir='${datadir}'
+       AC_SUBST(datarootdir)
+fi
+
+if test "$docdir" = ""; then
+       docdir='${datarootdir}/doc/${PACKAGE}'
+       AC_SUBST(docdir)
+fi
+
+if test "$htmldir" = ""; then
+       htmldir='${docdir}'
+       AC_SUBST(htmldir)
+fi
+
+if test "$pdfdir" = ""; then
+       pdfdir='${docdir}'
+       AC_SUBST(pdfdir)
+fi
+
 #swig
 AC_PATH_PROG(SWIG, swig, "no")
 if test "$SWIG" == "no" ; then