Tracerestrict: Add enum type for TRIT_LONG_RESERVE values

src/tracerestrict.cpp

@@ -678,10 +678,18 @@ void TraceRestrictProgram::Execute(const Train* v, const TraceRestrictProgramInp
 						break;
 
 					case TRIT_LONG_RESERVE:
-						if (GetTraceRestrictValue(item)) {
-							out.flags &= ~TRPRF_LONG_RESERVE;
-						} else {
-							out.flags |= TRPRF_LONG_RESERVE;
+						switch (static_cast<TraceRestrictLongReserveValueField>(GetTraceRestrictValue(item))) {
+							case TRLRVF_LONG_RESERVE:
+								out.flags |= TRPRF_LONG_RESERVE;
+								break;
+
+							case TRLRVF_CANCEL_LONG_RESERVE:
+								out.flags &= ~TRPRF_LONG_RESERVE;
+								break;
+
+							default:
+								NOT_REACHED();
+								break;
 						}
 						break;
 

src/tracerestrict.h

@@ -269,6 +269,14 @@ enum TraceRestrictTargetDirectionCondAuxField {
 	/* space up to 3 */
 };
 
+/**
+ * TraceRestrictItem value field, for TRIT_LONG_RESERVE
+ */
+enum TraceRestrictLongReserveValueField {
+	TRLRVF_LONG_RESERVE                = 0,       ///< Long reserve
+	TRLRVF_CANCEL_LONG_RESERVE         = 1,       ///< Cancel long reserve
+};
+
 /**
  * TraceRestrictItem value field, for TRIT_WAIT_AT_PBS
  */
@@ -697,7 +705,7 @@ enum TraceRestrictValueType {
 	TRVT_TILE_INDEX               = 8, ///< takes a TileIndex in the next item slot
 	TRVT_PF_PENALTY               = 9, ///< takes a pathfinder penalty value or preset index, as per the auxiliary field as type: TraceRestrictPathfinderPenaltyAuxField
 	TRVT_RESERVE_THROUGH          = 10,///< takes a value 0 = reserve through, 1 = cancel previous reserve through
-	TRVT_LONG_RESERVE             = 11,///< takes a value 0 = long reserve, 1 = cancel previous long reserve
+	TRVT_LONG_RESERVE             = 11,///< takes a TraceRestrictLongReserveValueField
 	TRVT_GROUP_INDEX              = 12,///< takes a GroupID
 	TRVT_WEIGHT                   = 13,///< takes a weight
 	TRVT_POWER                    = 14,///< takes a power

src/tracerestrict_gui.cpp

@@ -1545,7 +1545,19 @@ static void DrawInstructionString(const TraceRestrictProgram *prog, TraceRestric
 				break;
 
 			case TRIT_LONG_RESERVE:
-				instruction_string = GetTraceRestrictValue(item) ? STR_TRACE_RESTRICT_LONG_RESERVE_CANCEL : STR_TRACE_RESTRICT_LONG_RESERVE;
+				switch (static_cast<TraceRestrictLongReserveValueField>(GetTraceRestrictValue(item))) {
+					case TRLRVF_LONG_RESERVE:
+						instruction_string = STR_TRACE_RESTRICT_LONG_RESERVE;
+						break;
+
+					case TRLRVF_CANCEL_LONG_RESERVE:
+						instruction_string = STR_TRACE_RESTRICT_LONG_RESERVE_CANCEL;
+						break;
+
+					default:
+						NOT_REACHED();
+						break;
+				}
 				break;
 
 			case TRIT_WAIT_AT_PBS:
@@ -3180,7 +3192,7 @@ private:
 							right_sel->SetDisplayedPlane(DPR_VALUE_DROPDOWN);
 							this->EnableWidget(TR_WIDGET_VALUE_DROPDOWN);
 							this->GetWidget<NWidgetCore>(TR_WIDGET_VALUE_DROPDOWN)->widget_data =
-									GetTraceRestrictValue(item) ? STR_TRACE_RESTRICT_LONG_RESERVE_CANCEL : STR_TRACE_RESTRICT_LONG_RESERVE;
+									GetDropDownStringByValue(&_long_reserve_value, GetTraceRestrictValue(item));
 							break;
 
 						case TRVT_WAIT_AT_PBS: