lets have an error message when creating the graph fails

git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk/program@1768 a5681a0c-68f1-0310-ab6d-d61299d08faa

diff --git a/src/rrd_graph.c b/src/rrd_graph.c
index eb90952..549e08c 100644 (file)
--- a/src/rrd_graph.c
+++ b/src/rrd_graph.c
@@ -3844,8 +3844,11 @@ int rrd_graph(
             (*prdata)[prlines] = NULL;
             strcpy((*prdata)[prlines - 1], walker->value.u_str);
         } else if (strcmp(walker->key, "image") == 0) {
-            fwrite(walker->value.u_blo.ptr, walker->value.u_blo.size, 1,
-                   (stream ? stream : stdout));
+            if ( fwrite(walker->value.u_blo.ptr, walker->value.u_blo.size, 1,
+                   (stream ? stream : stdout)) == 0 && ferror(stream ? stream : stdout)){
+                rrd_set_error("writing image");
+                return 0;
+            }
         }
         /* skip anything else */
         walker = walker->next;