Index out of bound crashes

[neroden]

Aaaaand the bridgewater-brunel game is now crashing reliably, always at the same point.  (It could be any number of things, I was fooling around with a lot of different stuff including one-way roads and overtaking, which seems to be somewhat questionable code.)

FATAL ERROR: vector_tpl<T>::[] - 14quickstone_tplI8convoi_tE: index out of bounds: 0 not in 0..4294967295
Aborting program execution ...

[jamespetts]

I have split this from the Bridgewater-Brunel no. 5 thread as that thread is not for posting bug reports.

I believe that I have now fixed this, which fix should be incorporated with the next nightly build. I should be grateful if anyone could confirm that this is successful.