(svn r2345) - Fix: Don't allow stuff to be renamed to nothing if we don't support it. Only valid ones are signs (delete) and waypoints (rename to default).

engine.c

@@ -887,7 +887,7 @@ int32 CmdRenameEngine(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 {
 	StringID str;
 
-	if (!IsEngineIndex(p1)) return CMD_ERROR;
+	if (!IsEngineIndex(p1) || _cmd_text[0] == '\0') return CMD_ERROR;
 
 	str = AllocateNameUnique(_cmd_text, 0);
 	if (str == 0) return CMD_ERROR;

misc_cmd.c

@@ -129,6 +129,8 @@ int32 CmdChangeCompanyName(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	StringID str;
 	Player *p;
 
+	if (_cmd_text[0] == '\0') return CMD_ERROR;
+
 	str = AllocateNameUnique(_cmd_text, 4);
 	if (str == 0) return CMD_ERROR;
 
@@ -153,6 +155,8 @@ int32 CmdChangePresidentName(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	StringID str;
 	Player *p;
 
+	if (_cmd_text[0] == '\0') return CMD_ERROR;
+
 	str = AllocateNameUnique(_cmd_text, 4);
 	if (str == 0) return CMD_ERROR;
 

station_cmd.c

@@ -2653,7 +2653,7 @@ int32 CmdRenameStation(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	StringID str,old_str;
 	Station *st;
 
-	if (!IsStationIndex(p1)) return CMD_ERROR;
+	if (!IsStationIndex(p1) || _cmd_text[0] == '\0') return CMD_ERROR;
 	st = GetStation(p1);
 
 	if (!IsValidStation(st) || !CheckOwnership(st->owner)) return CMD_ERROR;

town_cmd.c

@@ -1447,7 +1447,7 @@ int32 CmdRenameTown(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	StringID str;
 	Town *t;
 
-	if (!IsTownIndex(p1)) return CMD_ERROR;
+	if (!IsTownIndex(p1) || _cmd_text[0] == '\0') return CMD_ERROR;
 
 	t = GetTown(p1);
 

vehicle.c

@@ -1654,7 +1654,7 @@ int32 CmdNameVehicle(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	Vehicle *v;
 	StringID str;
 
-	if (!IsVehicleIndex(p1)) return CMD_ERROR;
+	if (!IsVehicleIndex(p1) || _cmd_text[0] == '\0') return CMD_ERROR;
 
 	v = GetVehicle(p1);