Sane failure for rides longer than a week, which usually happen because

someone sets the date on their PT and doesn't reset the device before going
for a ride.  This fix will keep GC working until the user splits the ride
(and until we add a ride-splitting function).

src/AllPlot.cpp

@@ -82,6 +82,14 @@ AllPlot::recalc()
     if (!timeArray)
         return;
     int rideTimeSecs = (int) ceil(timeArray[arrayLength - 1]);
+    if (rideTimeSecs > 7*24*60*60) {
+        QwtArray<double> data;
+        wattsCurve->setData(data, data);
+        hrCurve->setData(data, data);
+        speedCurve->setData(data, data);
+        cadCurve->setData(data, data);
+        return;
+    }
     double totalWatts = 0.0;
     double totalHr = 0.0;
     double totalSpeed = 0.0;

src/CpintPlot.cpp

@@ -118,6 +118,10 @@ update_cpi_file(const cpi_file_info *info, QProgressDialog *progress,
     assert(out);
 
     int total_secs = (int) ceil(data.points.back().secs);
+    if (total_secs > 7*24*60*60) {
+        fclose(out);
+        return;
+    }
     double *bests = (double*) calloc(total_secs + 1, sizeof(double));
 
     bool canceled = false;