if stacking on nothing we should not try to figure out WHAT we stacked on since this...

git-svn-id: svn://svn.oetiker.ch/rrdtool/branches/1.2/program@488 a5681a0c-68f1-0310-ab6d-d61299d08faa

diff --git a/src/rrd_graph.c b/src/rrd_graph.c
index a5f87db..01e174c 100644 (file)
--- a/src/rrd_graph.c
+++ b/src/rrd_graph.c
@@ -2482,7 +2482,7 @@ graph_paint(image_desc_t *im, char ***calcpr)
                continue;
            }
             ytop = ytr(im,im->gdes[i].p_data[ii]);
-           if ( im->gdes[i].stack ) {
+           if ( lastgdes && im->gdes[i].stack ) {
                   ybase = ytr(im,lastgdes->p_data[ii]);
             } else {
                   ybase = ytr(im,areazero);