fix segfault on non-existent RRD file when using rrdcached

diff --git a/src/rrd_graph.c b/src/rrd_graph.c
index 6a380186ba2a56377e94e61cb5ff9990d64baf2b..a03c4bb8ce276a7f95ff358474633150818b9e60 100644 (file)
--- a/src/rrd_graph.c
+++ b/src/rrd_graph.c
@@ -3794,7 +3794,7 @@ int graph_paint(
     }
 
     /* pull the data from the rrd files ... */
-    if (data_fetch(im) == -1)
+    if (data_fetch(im) != 0)
         return -1;
     /* evaluate VDEF and CDEF operations ... */
     if (data_calc(im) == -1)