fix NRE in dv calculator

JonnyOThan · JonnyOThan · commit 643f97562a84 · 2023-02-14T13:13:24.000-05:00
diff --git a/RasterPropMonitor/Core/RPMCEvaluators.cs b/RasterPropMonitor/Core/RPMCEvaluators.cs
@@ -3101,9 +3101,10 @@ private NumericVariableEvaluator DeltaVStage()
             {
                 return (RPMVesselComputer comp) =>
                 {
-                    if (comp?.vessel.VesselDeltaV != null)
+                    var stageInfo = comp?.vessel?.VesselDeltaV?.GetStage(comp.vessel.currentStage);
+                    if (stageInfo != null)
                     {
-                        return comp.vessel.VesselDeltaV.GetStage(comp.vessel.currentStage).deltaVActual;
+                        return stageInfo.deltaVActual;
                     }
                     return (comp.actualAverageIsp * RPMGlobals.gee) * Math.Log(comp.totalShipWetMass / (comp.totalShipWetMass - comp.resources.PropellantMass(true)));
                 };

Original file line number	Diff line number	Diff line change
`@@ -3101,9 +3101,10 @@ private NumericVariableEvaluator DeltaVStage()`
`3101`	`3101`	`{`
`3102`	`3102`	`return (RPMVesselComputer comp) =>`
`3103`	`3103`	`{`
`3104`		`- if (comp?.vessel.VesselDeltaV != null)`
	`3104`	`+ var stageInfo = comp?.vessel?.VesselDeltaV?.GetStage(comp.vessel.currentStage);`
	`3105`	`+ if (stageInfo != null)`
`3105`	`3106`	`{`
`3106`		`- return comp.vessel.VesselDeltaV.GetStage(comp.vessel.currentStage).deltaVActual;`
	`3107`	`+ return stageInfo.deltaVActual;`
`3107`	`3108`	`}`
`3108`	`3109`	`return (comp.actualAverageIsp * RPMGlobals.gee) * Math.Log(comp.totalShipWetMass / (comp.totalShipWetMass - comp.resources.PropellantMass(true)));`
`3109`	`3110`	`};`