Prevent NPE if there is not relationship between resource and type of hours via cost category

In that case the default price for the hours type is used.

FEA: ItEr76S17MoneyCostMonitoringSystem

libreplan-business/src/main/java/org/libreplan/business/planner/entities/IMoneyCostCalculator.java

@@ -38,7 +38,11 @@ public interface IMoneyCostCalculator {
      * following formula:<br />
      * <tt>Sum of all the hours devoted to a task multiplied by the cost of
      * each hour according to these parameters (type of hour, cost category of
-     * the resource, date of the work report)</tt>
+     * the resource, date of the work report)</tt><br />
+     *
+     * If there is not relationship between resource and type of hour through
+     * the cost categories, the price used is the default one for the type of
+     * hour.
      *
      * @param The
      *            {@link OrderElement} to calculate the money cost

libreplan-business/src/main/java/org/libreplan/business/planner/entities/MoneyCostCalculator.java

@@ -66,6 +66,13 @@ public class MoneyCostCalculator implements IMoneyCostCalculator {
                             workReportLine.getResource(),
                             workReportLine.getLocalDate(),
                             workReportLine.getTypeOfWorkHours());
+
+            // If cost undefined via CostCategory get it from type
+            if (priceCost == null) {
+                priceCost = workReportLine.getTypeOfWorkHours()
+                        .getDefaultPrice();
+            }
+
             BigDecimal cost = priceCost.multiply(workReportLine.getEffort()
                     .toHoursAsDecimalWithScale(2));
             result = result.add(cost);