krb5 commit: Fix sendto_kdc.c on OS X after cm refactoring

[Greg Hudson]

https://github.com/krb5/krb5/commit/82aa5f56acee4d63800a1a69794a2d7bc4f104fc
commit 82aa5f56acee4d63800a1a69794a2d7bc4f104fc
Author: Greg Hudson <ghudson at mit.edu>
Date:   Fri Apr 4 14:58:33 2014 -0400

    Fix sendto_kdc.c on OS X after cm refactoring
    
    Treat POLLHUP without POLLIN or POLLOUT as an exception in the poll
    version of cm_get_ssflags, to correctly handle TCP connection errors
    on OS X.

 src/lib/krb5/os/sendto_kdc.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/src/lib/krb5/os/sendto_kdc.c b/src/lib/krb5/os/sendto_kdc.c
index e773a0a..67e2a60 100644
--- a/src/lib/krb5/os/sendto_kdc.c
+++ b/src/lib/krb5/os/sendto_kdc.c
@@ -179,6 +179,15 @@ cm_get_ssflags(struct select_state *selstate, int fd)
 {
     struct pollfd *pfd = find_pollfd(selstate, fd);
 
+    /*
+     * OS X sets POLLHUP without POLLOUT on connection error.  Catch this as
+     * well as other error events such as POLLNVAL, but only if POLLIN and
+     * POLLOUT aren't set, as we can get POLLHUP along with POLLIN with TCP
+     * data still to be read.
+     */
+    if (pfd->revents != 0 && !(pfd->revents & (POLLIN | POLLOUT)))
+        return SSF_EXCEPTION;
+
     return ((pfd->revents & POLLIN) ? SSF_READ : 0) |
         ((pfd->revents & POLLOUT) ? SSF_WRITE : 0) |
         ((pfd->revents & POLLERR) ? SSF_EXCEPTION : 0);