OpenTTD's known bugs

Last updated:    2009-08-18

Release version: 0.7.2

Table of Contents:

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1) About

2) Known bugs in the this stable release

3) Known bugs that will not be solved

1) About:

-- ------

2) Known bugs in the this stable release:

-- --------------------------------------

The following bugs are known to exist in this stable release and

we intend to fix them. Some bugs are known but are not fixable or

fixing them would cause further problems. Those bugs can be found

in the "Known bugs that will not be solved" section.

The bugs in this section all refer to a ticket in our bug tracking system

that you can find at: http://bugs.openttd.org

If the bugs are closed but still listed here it means that the bug is fixed

and that the nightlies and next major release will not have that bug.

3) Known bugs that will not be solved:

-- -----------------------------------

This section lists all known bugs that we do not intend to fix and the

reasons why we think that fixing them is infeasible. We might make some

minor improvements that reduce the scope of these bugs, but we will not

be able to completely fix them.

Clipping problems

	In some cases sprites are not drawn as one would expect. Examples of

	this are aircraft that might be hidden below the runway or trees that

	in some cases are rendered over vehicles.

	The primary cause of this problem is that OpenTTD does not have enough

	data (like a 3D model) to properly determine what needs to be drawn in

	front of what. OpenTTD has bounding boxes but in lots of cases they

	are either too big or too small and then cause problems with what

	needs to be drawn in front of what. Also some visual tricks are used.

	For example trains at 8 pixels high, the catenary needs to be drawn

	above that. When you want to draw bridges on top of that, which are

	only one height level (= 8 pixels) higher, you are getting into some

	big problems.

	We can not change the height levels; it would require us to either

	redraw all vehicle or all landscape graphics. Doing so would mean we

	leave the Transport Tycoon graphics, which in effect means OpenTTD

	will not be a Transport Tycoon clone anymore.

Duplicate (station) names after renaming

	After renaming stations one can create duplicate station names. This

	is done giving a station the same custom name as another station with

	an automatically generated name.

	The major part of this problem is that station names are translatable.

	Meaning that a station is called e.g. '<TOWN> Central' in English and

	'<TOWN> Centraal' in Dutch. This means that in network games the

	renaming of a town could cause the rename to succeed on some clients

	and fail at others. This creates an inconsistent game state that will

	be seen as a 'desync'. Secondly the custom names are intended to fall

	completely outside of the '<TOWN> <name>' naming of stations, so when

	you rename a town all station names are updated accordingly.

	As a result the decision has been made that all custom names are only

	compared to the other custom names in the same class and not compared

	to the automatically generated names.

Forbid 90 degree turns does not work for crossing PBS paths

	When you run a train through itself on a X junction with PBS turned on

	the train will not obey the 'forbid 90 degree turns' setting. This is

	due to the fact that we can not be sure that the setting was turned

	off when the track was reserved, which means that we assume it was

	turned on and that the setting does not hold at the time. We made it

	this way to allow one to change the setting in-game, but it breaks

	slightly when you are running your train through itself. Running a

	train through means that your network is broken and is thus a user

	error which OpenTTD tries to graciously handle.

	Fixing this bug means that we need to record whether this particular

	setting was turned on or off at the time the reservation was made. This

	means adding quite a bit of data to the savegame for solving an issue

	that is basically an user error. We think it is not worth the effort.

Lost trains ignore (block) exit signals

	If trains are lost they ignore block exit signals, blocking junctions

	with presignals. This is caused because the path finders cannot tell

	where the train needs to go. As such a random direction is chosen at

	each junction. This causes the trains to occasionally to make choices

	that are unwanted from a player's point of view.

	This will not be fixed because lost trains are in almost all cases a

	network problem, e.g. a train can never reach a specific place. This

	makes the impact of fixing the bug enormously small against the

	amount of work needed to write a system that prevents the lost trains

	from taking the wrong direction.

First of all, check whether the bug is not already known. Do this by looking

through the file called 'known-bugs.txt' which is distributed with OpenTTD

like this readme.

For tracking our bugs we are using a bug tracker called Flyspray. You can find

the tracker at http://bugs.openttd.org/. Before actually reporting take a look

through the already reported bugs there to see if the bug is already known.

The 'known-bugs.txt' file might be a bit outdated at the moment you are

reading it as only bugs known before the release are documented there. Also

look through the recently closed bugs.

When you are sure it is not already reported you should:

 * Make sure you are running a recent version, i.e. run the latest stable or

   nightly based on where you found the bug.

 * Make sure you are not running a non-official binary, like a patch pack.

   When you are playing with a patch pack you should report any bugs to the

   forum thread related to that patch pack.

 * Make it reproducable for the developers. In other words, create a savegame

   in which you can reproduce the issue once loaded. It is very useful to give

   us the crash.dmp, crash.sav and crash.log which are created on crashes.

 * Check whether the bug is already reported on our bug tracker. This includes

   searching for recently closed bug reports as the bug might already be fixed.

After you have done all that you can report the bug. Please include the

following information in your bug report:

 * OpenTTD version (PLEASE test the latest SVN/nightly build)

 * Bug details, including instructions how to reproduce it

 * Platform (Win32, Linux, FreeBSD, ...) and compiler (including version) if

   you compiled OpenTTD yourself.

 * Attach a saved game *and* a screenshot if possible

 * If this bug only occurred recently please note the last version without

   the bug and the first version including the bug. That way we can fix it

   quicker by looking at the changes made.

 * Attach crash.dmp, crash.log and crash.sav. These files are usually created

   next to your openttd.cfg. The crash handler will tell you the location.