* fix error messages for bad input

diff --git a/src/rrd_diff.c b/src/rrd_diff.c
index 93769508aeea92a09ddce3d21c431ffe21b76ac9..367b9e62f27ee48d0b9ad70982c8fb66890aaa84 100644 (file)
--- a/src/rrd_diff.c
+++ b/src/rrd_diff.c
@@ -84,14 +84,14 @@ double rrd_diff(
                 c = 0;
             }
         }
-        if (rrd_strtodbl(res, NULL, &result, 'expected a number') != 2){
+        if (rrd_strtodbl(res, NULL, &result, "expected a number") != 2){
             result = DNAN;
         }
         else {
             result = -result;
         }
     } else {
-        if (rrd_strtodbl(res, NULL, &result, 'expected a number') != 2){
+        if (rrd_strtodbl(res, NULL, &result, "expected a number") != 2){
             result = DNAN;
         }
     }