[dunecontrol]

Use BUILDIR from opts file only if not empty string (=is set).

[[Imported from SVN: r6955]]

bin/dunecontrol

@@ -165,7 +165,11 @@ load_opts() {
   local CMD_FLAGS_FROM_FILE=""
   BUILDDIR=$DUNE_BUILDDIR
   if test "x$DUNE_OPTS_FILE" != "x"; then
-    BUILDDIR="$(eval BUILDDIR=""; . $DUNE_OPTS_FILE; eval echo \$BUILDDIR)"
+    # use build dir from opts file if set
+    OPS_FILE_BUILDDIR="$(eval BUILDDIR=""; . $DUNE_OPTS_FILE; eval echo \$BUILDDIR)"
+    if test -n "$OPS_FILE_BUILDDIR"; then
+      BUILDDIR="$OPS_FILE_BUILDDIR"
+    fi
     CMAKE_FLAGS="$(. $DUNE_OPTS_FILE; eval echo \$CMAKE_FLAGS)"
     CMD_FLAGS_FROM_FILE="$(eval ${COMMAND}_FLAGS=""; . $DUNE_OPTS_FILE; eval echo \$${COMMAND}_FLAGS)"
   fi