Crazy track build

[Steve]

The Bug
Diagonal track will be automatically be built until it reaches a blockage.

Steps to reproduce
Load up vanilla TTDPatch and open a game.
From the track window, select either the vertical or horizontal piece.
Click and hold the left mouse on anywhere on the map what is valid for the piece.
Move the mouse onto any non-map part of the screen, such as the toolbar, other windows, outside TTD (in windowed mode).
Wait for the white boxes to dissapear (necessary when going off the screen) and release the mouse.
Track is built from where you clicked the mouse, continuesly until it finds a blockage.

[Mek]

Diagonal track will be automatically be built until it reaches a blockage.

Not entirely true... if there are no blockages it will build a seemingly random number of tiles... Even the direction in wich it is built seems to be random

Wait for the white boxes to dissapear (necessary when going off the screen) and release the mouse.

You don't have to wait for the white boxes to dissapear, in fact sometimes they won't dissapear at all... Apparently i've got it wrong in more than one place...

I don't know yet what is causing it (in fact i haven't the slightest idea, my code looks like it should work..), but i'll certainly look into it...

[Steve]

It looks to me as if you're not setting the end position of the diagonal track properly, or it is being set at a default value that can't be reached. Therefore, the game just keeps building track until it's physically impossible.
It's not being set because you're not letting the mouse go on the map itself, so the process needs to be cancelled.

As for the white lines dissapearing, you're correct, it isn't always necessary, but I noticed that sometimes when you dragged off the screen, it would still highlight and build the correct amount until a few seconds had passed and the white outline dissapeared.