reat nan as FALSE in an IF CDEF

[rrdtool.git] / src / rrd_rpncalc.c

diff --git a/src/rrd_rpncalc.c b/src/rrd_rpncalc.c
index 839643b..1f86f2e 100644 (file)
--- a/src/rrd_rpncalc.c
+++ b/src/rrd_rpncalc.c
@@ -705,8 +705,8 @@ short rpn_calc(
             break;
         case OP_IF:
             stackunderflow(2);
-            rpnstack->s[stptr - 2] = rpnstack->s[stptr - 2] != 0.0 ?
-                rpnstack->s[stptr - 1] : rpnstack->s[stptr];
+            rpnstack->s[stptr - 2] = ( isnan(rpnstack->s[stptr - 2]) || rpnstack->s[stptr - 2] == 0.0 ) ?
+                rpnstack->s[stptr] : rpnstack->s[stptr - 1];
             stptr--;
             stptr--;
             break;