abort if $TOPDIR is empty

diff --git a/build b/build
index 333e8bb..124adf1 100755 (executable)
--- a/build
+++ b/build
@@ -1516,6 +1516,10 @@ for SPECFILE in "${SPECFILES[@]}" ; do
 
     if test "$BUILDTYPE" = spec ; then
        TOPDIR=`chroot $BUILD_ROOT su -c "rpm --eval '%_topdir'" - $BUILD_USER`
+       if test -z "$TOPDIR"; then
+           echo "Error: TOPDIR empty"
+           cleanup_and_exit 1
+       fi
     else
        TOPDIR=/usr/src/packages
        mkdir -p $BUILD_ROOT$TOPDIR