jsrrdgraph: Fix undefined value issue in RrdDataFile

`RRDRRAInfo.pdp_cnt` does not exist. A reference to the pdp_cnt member
in a struct exists, this is available via the `getPdpPerRow()` method,
so use that. (actually, `getMinStep() * getPdpPerRow()` can be
simplified further, see below).

While at it, replace the combination
`RRDRRAInfo.getPdpPerRow() * RRAInfo.pdp_step` by `RRDRRAInfo.getStep()`
since this is the same thing. As `RRDHeader.pdp_step` is copied into
`RRDRRAInfo`, this can also be substituted.

1 files changed, 6 insertions, 4 deletions

diff --git a/js/RrdDataFile.js b/js/RrdDataFile.js
index 2c0e846..08cc3ae 100644
--- a/js/RrdDataFile.js
+++ b/js/RrdDataFile.js
@@ -60,11 +60,13 @@ RrdDataFile.prototype = {
                 for (i = 0; i < rra_cnt; i++) {
                         rra = rrd.getRRAInfo(i);
                         if (RrdGraphDesc.cf_conv(rra.getCFName()) === cf_idx) {
-                                cal_end = (rrd.getLastUpdate() - (rrd.getLastUpdate() % (rra.getPdpPerRow() * rra.pdp_step)));
-                                cal_start = (cal_end - (rra.getPdpPerRow() * rra.row_cnt * rra.pdp_step));
+                                /* covered seconds in this RRA */
+                                var range_secs = rra.getStep();
+                                cal_end = rrd.getLastUpdate() - (rrd.getLastUpdate() % range_secs);
+                                cal_start = cal_end - (range_secs * rra.row_cnt);
                                 full_match = gdp.end - gdp.start;
 
-                                tmp_step_diff = Math.abs(ft_step - (rrd.getMinStep() * rra.pdp_cnt));
+                                tmp_step_diff = Math.abs(ft_step - range_secs);
                                 if (cal_start <= gdp.start) {
                                         if (first_full || (tmp_step_diff < best_full_step_diff)) {
                                                 first_full = 0;
@@ -91,7 +93,7 @@ RrdDataFile.prototype = {
                 var rra_info = rrd.getRRAInfo(chosen_rra);
                 rra = rrd.getRRA(chosen_rra);
 
-                ft_step = rrd.rrd_header.pdp_step * rra_info.getPdpPerRow();
+                ft_step = rra_info.getStep();
                 gdp.start -= (gdp.start % ft_step);
                 gdp.end += (ft_step - gdp.end % ft_step);
                 rows = (gdp.end - gdp.start) / ft_step + 1;