(svn r21975) -Add: console command to reset the engine pool. It removes the traces of engines which are no longer associated to a NewGRF, and can be used to e.g. 'fix' scenarios which were screwed up by the author. You can only use it when there are no vehicles in the game though.

src/terraform_gui.cpp

@@ -31,6 +31,7 @@
 #include "newgrf_object.h"
 #include "object.h"
 #include "hotkeys.h"
+#include "engine_base.h"
 
 #include "table/strings.h"
 
@@ -560,6 +561,9 @@ static void ResetLandscapeConfirmationCallback(Window *w, bool confirmed)
 			if (!st->IsInUse()) delete st;
 		}
 
+		/* Now that all vehicles are gone, we can reset the engine pool. Maybe it reduces some NewGRF changing-mess */
+		EngineOverrideManager::ResetToCurrentNewGRFConfig();
+
 		MarkWholeScreenDirty();
 	}
 }