Exception reading rawTrack

[devemux86]

This can often happen when we do a lot of route testing and a termination of BRouter.

There is a *_rawtrack.dat file in /brouter/modes/ folder but with 0 size!

Then BRouter hangs as it can't read the rawtrack file, it keeps throwing an exception
and user must delete the file manually (not possible in new Android and data folder)
or re-download any route segment.

As OsmTrack.readBinary already returns a null result, we should not also throw a RunTimeException here?

https://github.com/abrensch/brouter/blob/master/brouter-core/src/main/java/btools/router/OsmTrack.java#L288

I can provide a pull request if you agree.

[devemux86]

Another similar user case was reported here:

• (only pedestrian) routing lost - how to recover or is it a bug? cgeo/cgeo#14759 (comment)