[Swan-commit] Changes to ref refs/heads/master

[Andrew Cagney]

New commits:
commit 4e041bfcbd33772498dea0a4b5722acced09ff9e
Author: Andrew Cagney <cagney at gnu.org>
Date:   Wed Sep 20 09:03:12 2017 -0400

    xauth-pam: instead of canceling the auth thread, leave it to die
    
    The function xauth_delete() (replaces xauth_cancel):
    
    - notifies the auth thread that it should abort
    - notifies the callback that the operation was aborted
    
    the auth thread is then left to quietly die on its own
    (cleaning up its resources, but skipping the callback).
    
    Its assumed that the PAM query does eventually die, if it
    doesn't, or we end up with too may dieing PAM threads,
    we'll need move PAM to its own process.
    
    This addresses several problems in glibc:
    
    - Race conditions in pthread cancellation
      https://sourceware.org/bugzilla/show_bug.cgi?id=12683
    
    - -fexceptions breaks pthread_cancel()
      https://sourceware.org/bugzilla/show_bug.cgi?id=14266
    
    - "PAM does not support thread cancellation"
      https://bugzilla.redhat.com/show_bug.cgi?id=1492861
    
    musl doesn't seem to have them.