bug#18065: guile hangs if strerror is called with invalid (non-int) argument

[Ian Price]

Your patch does solve this issue, but I'm not 100% why the problem
occurs in the first place, as the lock should have been unlocked when
the throw occurred.

If I catch the wrong type error explicitly, then there is no problem.

scheme@(guile-user)> (catch #t (lambda () (strerror 1.5)) list)
$1 = (wrong-type-arg #f "Wrong type (expecting ~A): ~S" ("exact integer" 1.5) 
(1.5))

My thinking is that the a pre-unwind handler in the repl tries to lock
the same mutex, but I haven't looked into this deeply enough.

-- 
Ian Price -- shift-reset.com

"Programming is like pinball. The reward for doing it well is
the opportunity to do it again" - from "The Wizardy Compiled"