(svn r18478) [0.7] -Backport from trunk:

- Fix: When moving a wagon and only the last part of a dual headed engine you could split the dual headed engine over two vehicles (r18462)
- Fix: [Windows] Forgot to load the symbol from SDL.dll (r18439)
- Fix: Do not run the 'jam protection' for vehicles in a depot [FS#3360] (r18428)
- Fix: [Windows] the help window would be too large in some cases [FS#3327] (r18424)
- Fix: Under some circumstances a pointer could be left untouched and then freed. Make sure this does not happen by ensuring it starts out as NULL instead of 'garbage' [FS#3298] (r18418)

src/train_cmd.cpp

@@ -965,10 +965,6 @@ static void AddWagonToConsist(Vehicle *v, Vehicle *dest)
  */
 static void NormaliseTrainConsist(Vehicle *v)
 {
-	if (IsFreeWagon(v)) return;
-
-	assert(IsFrontEngine(v));
-
 	for (; v != NULL; v = GetNextVehicle(v)) {
 		if (!IsMultiheaded(v) || !IsTrainEngine(v)) continue;