(svn r13626) -Fix (r11871): signals were not updated when player removed signals from nonexistent track sharing bits with existing track
So disallow removing signals from nonexistent track
--- a/src/rail_cmd.cpp Tue Jun 24 15:58:01 2008 +0000
+++ b/src/rail_cmd.cpp Tue Jun 24 23:38:10 2008 +0000
@@ -1113,6 +1113,7 @@
if (!ValParamTrackOrientation(track) ||
!IsTileType(tile, MP_RAILWAY) ||
+ !HasTrack(tile, track) ||
!EnsureNoTrainOnTrack(tile, track) ||
!HasSignalOnTrack(tile, track)) {
return CMD_ERROR;