Pathfinding issue with impassable Tiberium

[Crimsonum]

First Check

• [X] I added a very descriptive title to this issue.
• [X] I used the GitHub search to find a similar issue and didn't find it.
• [X] I have attached as much information as possible (screenshots, debug and exception logs, etc).

Description

Tiberian Sun has an all but unused Tiberium type, Cruentus, which appears as large, impassable, unharvestable crystalline formations. For unknown reasons, this Tiberium type was mostly rejected, with a comment in rules.ini hinting it may have had something to do with the game's AI. This Tiberium type seems to work fine except for the fact that any non-preplaced Cruentus overlay will cause issues for pathfinding. In other words, if you enable Cruentus to grow and spread (it does not spread by default), units will have trouble pathfinding around the overlay.

This bug is not limited to just Cruentus; any Tiberium overlay, if made impassable, will cause issues with pathfinding. However, preplaced Cruentus overlay (BTIB##) is the only one which doesn't cause pathfinding issues. This may have to do with the fact that the game overrides any preplaced Cruentus overlay to use only the first Cruentus overlay type, BTIB01.

This bug might be related to another Tiberium-pathfinding bug: #17

Required Code (optional)

There are two ways to reproduce this bug:

Option A: Enable Cruentus to grow and spread

[Cruentus]
Growth=900 ;one in-game minute
GrowthPercentage=1.0 ;100%
Spread=900
SpreadPercentage=1.0

Option B: Make another Tiberium type impassable

To make a Tiberium type impassable, you need to add the following code to all the Tiberium type overlay types (e.g. `TIB01`-`TIB20`):
[TIB##]
Land=Rock
NoUseTileLandType=true

Steps To Reproduce

I have attached a test map where you can quickly reproduce the issue.

1. Download the test map.
2. Unzip to your Tiberian Sun directory.
3. Launch the GDI campaign.
4. Move your units around the red Tiberium to the top left.

Expected Behaviour

Units should have no trouble moving around the Tiberium.

Actual Behaviour

Units can't map a path around the Tiberium and get stuck.

Additional Context

As you can see, the impassable red Tiberium (modified Aboreus) causes pathfinding issues, while the impassable, non-spreading big blue crystals (Cruentus) don't.

Download test map