Avoid panic in drop?

[bvssvni]

There are couple places where it panics on drop, which will cause the task to be aborted.

https://github.com/PistonDevelopers/freetype-rs/blob/master/src/face.rs#L311-L324

https://github.com/PistonDevelopers/freetype-rs/blob/master/src/library.rs#L99-L108

[andrewrk]

Panic on drop does not necessarily cause the task to be aborted. Abortion happens when the task is unwinding due to another panic. During this time destructors are called, and if another panic happens, then the task is aborted.

http://doc.rust-lang.org/reference.html#thread

[bvssvni]

@andrewrk Thanks for correcting me!

Perhaps we should print out to stderr instead on drop?

[andrewrk]

stderr is better than stdout, but I think the panic is the correct behavior here. In normal circumstances, a drop could trigger a panic and that would be the expected behavior. In circumstances where the program is already panicking, it could trigger an abort, but even that is the right behavior if so many critical errors are happening.