Merge branch 'tracerestrict' into tracerestrict-sx

src/tracerestrict.cpp

@@ -647,8 +647,9 @@ void TraceRestrictCreateProgramMapping(TraceRestrictRefId ref, TraceRestrictProg
 
 /**
  * Remove a program mapping
+ * @return true if a mapping was actually removed
  */
-void TraceRestrictRemoveProgramMapping(TraceRestrictRefId ref)
+bool TraceRestrictRemoveProgramMapping(TraceRestrictRefId ref)
 {
 	TraceRestrictMapping::iterator iter = _tracerestrictprogram_mapping.find(ref);
 	if (iter != _tracerestrictprogram_mapping.end()) {
@@ -678,6 +679,9 @@ void TraceRestrictRemoveProgramMapping(TraceRestrictRefId ref)
 				}
 			}
 		}
+		return true;
+	} else {
+		return false;
 	}
 }
 
@@ -717,8 +721,9 @@ TraceRestrictProgram *GetTraceRestrictProgram(TraceRestrictRefId ref, bool creat
 void TraceRestrictNotifySignalRemoval(TileIndex tile, Track track)
 {
 	TraceRestrictRefId ref = MakeTraceRestrictRefId(tile, track);
-	TraceRestrictRemoveProgramMapping(ref);
+	bool removed = TraceRestrictRemoveProgramMapping(ref);
 	DeleteWindowById(WC_TRACE_RESTRICT, ref);
+	if (removed) InvalidateWindowClassesData(WC_TRACE_RESTRICT);
 }
 
 /**
@@ -1003,6 +1008,10 @@ CommandCost CmdProgramSignalTraceRestrictProgMgmt(TileIndex tile, DoCommandFlag
 		}
 	}
 
+	if (type != TRDCT_PROG_RESET && !TraceRestrictProgram::CanAllocateItem()) {
+		return CMD_ERROR;
+	}
+
 	if (!(flags & DC_EXEC)) {
 		return CommandCost();
 	}

src/tracerestrict.h

@@ -513,7 +513,7 @@ static inline Track GetTraceRestrictRefIdTrack(TraceRestrictRefId ref)
 }
 
 void TraceRestrictCreateProgramMapping(TraceRestrictRefId ref, TraceRestrictProgram *prog);
-void TraceRestrictRemoveProgramMapping(TraceRestrictRefId ref);
+bool TraceRestrictRemoveProgramMapping(TraceRestrictRefId ref);
 
 TraceRestrictProgram *GetTraceRestrictProgram(TraceRestrictRefId ref, bool create_new);