8634 epoll fails to wake on certain edge-triggered conditions
8635 epoll should not emit POLLNVAL
8636 recursive epoll should emit EPOLLRDNORM
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Igor Kozhukhov <igor@dilos.org>

*** 20,29 ****
--- 20,30 ----
   */
  
  /*
   * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
+  * Copyright 2017 Joyent, Inc.
   */
  
  
  /*
   * srn  Provide apm-like interfaces to Xorg
*** 261,274 ****
          clone = SRN_MINOR_TO_CLONE(getminor(dev));
          if ((events & (POLLIN | POLLRDNORM)) && srn_poll_cnt[clone]) {
                  *reventsp |= (POLLIN | POLLRDNORM);
          } else {
                  *reventsp = 0;
!                 if (!anyyet) {
                          *phpp = &srn_pollhead[clone];
                  }
-         }
          return (0);
  }
  
  /*ARGSUSED*/
  static int
--- 262,276 ----
          clone = SRN_MINOR_TO_CLONE(getminor(dev));
          if ((events & (POLLIN | POLLRDNORM)) && srn_poll_cnt[clone]) {
                  *reventsp |= (POLLIN | POLLRDNORM);
          } else {
                  *reventsp = 0;
!         }
! 
!         if ((*reventsp == 0 && !anyyet) || (events & POLLET)) {
                  *phpp = &srn_pollhead[clone];
          }
          return (0);
  }
  
  /*ARGSUSED*/
  static int