diff -up cups-1.4.7/scheduler/avahi.c.avahi-4-poll cups-1.4.7/scheduler/avahi.c
--- cups-1.4.7/scheduler/avahi.c.avahi-4-poll	2011-06-28 12:54:34.651228409 +0100
+++ cups-1.4.7/scheduler/avahi.c	2011-06-28 12:54:34.652228391 +0100
@@ -0,0 +1,445 @@
+/*
+ * "$Id$"
+ *
+ *   Avahi poll implementation for the CUPS scheduler.
+ *
+ *   Copyright (C) 2010 Red Hat, Inc.
+ *   Authors:
+ *    Tim Waugh <twaugh@redhat.com>
+ *
+ *   Distribution and use rights are outlined in the file "LICENSE.txt"
+ *   "LICENSE" which should have been included with this file.  If this
+ *   file is missing or damaged, see the license at "http://www.cups.org/".
+ *
+ * Contents:
+ *
+ *   watch_read_cb         - Read callback for file descriptor
+ *   watch_write_cb        - Write callback for file descriptor
+ *   watched_fd_add_select() - Call cupsdAddSelect() as needed
+ *   watch_new()           - Create a new file descriptor watch
+ *   watch_free()          - Free a file descriptor watch
+ *   watch_update()        - Update watched events for a file descriptor
+ *   watch_get_events()    - Get events that happened for a file descriptor
+ *   timeout_cb()          - Run a timed Avahi callback
+ *   timeout_new()         - Set a wakeup time
+ *   timeout_update()      - Update the expiration time for a timeout
+ *   timeout_free()        - Free a timeout
+ *   compare_watched_fds() - Compare watched file descriptors for array sorting
+ *   compare_timeouts()    - Compare timeouts for array sorting
+ *   avahi_cups_poll_new() - Create a new Avahi main loop object for CUPS
+ *   avahi_cups_poll_free() - Free an Avahi main loop object for CUPS
+ *   avahi_cups_poll_get() - Get the abstract poll API structure
+ */
+
+#include <config.h>
+
+#ifdef HAVE_AVAHI /* Applies to entire file... */
+
+/*
+ * Include necessary headers...
+ */
+
+#include "cupsd.h"
+
+#if defined(HAVE_MALLOC_H) && defined(HAVE_MALLINFO)
+#  include <malloc.h>
+#endif /* HAVE_MALLOC_H && HAVE_MALLINFO */
+
+#ifdef HAVE_AVAHI
+#  include <avahi-common/timeval.h>
+#endif /* HAVE_AVAHI */
+
+
+typedef struct
+{
+  AvahiCupsPoll *cups_poll;
+
+  int fd;
+  AvahiWatchEvent occurred;
+  cups_array_t *watches;
+} cupsd_watched_fd_t;
+
+struct AvahiWatch
+{
+  cupsd_watched_fd_t *watched_fd;
+
+  AvahiWatchEvent events;
+  AvahiWatchCallback callback;
+  void *userdata;
+};
+
+struct AvahiTimeout
+{
+  AvahiCupsPoll *cups_poll;
+  AvahiTimeoutCallback callback;
+  void *userdata;
+  cupsd_timeout_t *cupsd_timeout;
+};
+
+/*
+ * Local functions...
+ */
+
+static AvahiWatch *	watch_new(const AvahiPoll *api,
+				  int fd,
+				  AvahiWatchEvent events,
+				  AvahiWatchCallback callback,
+				  void *userdata);
+static void		watch_free(AvahiWatch *watch);
+static void		watch_update(AvahiWatch *watch,
+				     AvahiWatchEvent events);
+static AvahiWatchEvent	watch_get_events(AvahiWatch *watch);
+static int		compare_watches(AvahiWatch *p0,
+					AvahiWatch *p1);
+
+
+/*
+ * 'watch_read_cb' - Read callback for file descriptor
+ */
+
+static void
+watch_read_cb (void *userdata)
+{
+  AvahiWatch *watch;
+  cupsd_watched_fd_t *watched_fd = userdata;
+  watched_fd->occurred |= AVAHI_WATCH_IN;
+  for (watch = (AvahiWatch *)cupsArrayFirst(watched_fd->watches);
+       watch;
+       watch = (AvahiWatch *)cupsArrayNext(watched_fd->watches)) {
+    if (watch->events & watched_fd->occurred) {
+      (watch->callback) (watch, watched_fd->fd,
+			 AVAHI_WATCH_IN, watch->userdata);
+      watched_fd->occurred &= ~AVAHI_WATCH_IN;
+      break;
+    }
+  }
+}
+
+
+/*
+ * 'watch_write_cb' - Write callback for file descriptor
+ */
+
+static void
+watch_write_cb (void *userdata)
+{
+  AvahiWatch *watch;
+  cupsd_watched_fd_t *watched_fd = userdata;
+  watched_fd->occurred |= AVAHI_WATCH_OUT;
+  for (watch = (AvahiWatch *)cupsArrayFirst(watched_fd->watches);
+       watch;
+       watch = (AvahiWatch *)cupsArrayNext(watched_fd->watches)) {
+    if (watch->events & watched_fd->occurred) {
+      (watch->callback) (watch, watched_fd->fd,
+			 AVAHI_WATCH_OUT, watch->userdata);
+      watched_fd->occurred &= ~AVAHI_WATCH_OUT;
+      break;
+    }
+  }
+}
+
+
+/*
+ * 'watched_fd_add_select' - Call cupsdAddSelect() as needed
+ */
+
+static int						/* O - Watches? */
+watched_fd_add_select (cupsd_watched_fd_t *watched_fd)
+{
+  AvahiWatch *watch;
+  cupsd_selfunc_t read_cb = NULL, write_cb = NULL;
+
+  for (watch = (AvahiWatch *)cupsArrayFirst(watched_fd->watches);
+       watch;
+       watch = (AvahiWatch *)cupsArrayNext(watched_fd->watches)) {
+    if (watch->events & (AVAHI_WATCH_IN |
+			     AVAHI_WATCH_ERR |
+			     AVAHI_WATCH_HUP)) {
+      read_cb = (cupsd_selfunc_t)watch_read_cb;
+      if (write_cb != NULL)
+	break;
+    }
+
+    if (watch->events & AVAHI_WATCH_OUT) {
+      write_cb = (cupsd_selfunc_t)watch_write_cb;
+      if (read_cb != NULL)
+	break;
+    }
+  }
+
+  if (read_cb || write_cb)
+    cupsdAddSelect (watched_fd->fd, read_cb, write_cb, watched_fd);
+  else
+    cupsdRemoveSelect (watched_fd->fd);
+
+  return (read_cb || write_cb);
+}
+
+/*
+ * 'watch_new' - Create a new file descriptor watch
+ */
+
+static AvahiWatch *
+watch_new (const AvahiPoll *api,
+	   int fd,
+	   AvahiWatchEvent events,
+	   AvahiWatchCallback callback,
+	   void *userdata)
+{
+  cupsd_watched_fd_t key, *watched_fd;
+  AvahiCupsPoll *cups_poll = api->userdata;
+  AvahiWatch *watch = malloc(sizeof(AvahiWatch));
+  if (watch == NULL)
+    return (NULL);
+
+  watch->events = events;
+  watch->callback = callback;
+  watch->userdata = userdata;
+
+  key.fd = fd;
+  watched_fd = cupsArrayFind (cups_poll->watched_fds, &key);
+  if (watched_fd == NULL) {
+    watched_fd = malloc(sizeof(cupsd_watched_fd_t));
+    if (watched_fd == NULL) {
+      free (watch);
+      return (NULL);
+    }
+
+    watched_fd->fd = fd;
+    watched_fd->occurred = 0;
+    watched_fd->cups_poll = cups_poll;
+    watched_fd->watches = cupsArrayNew ((cups_array_func_t)compare_watches,
+					NULL);
+  }
+
+  watch->watched_fd = watched_fd;
+  cupsArrayAdd(watched_fd->watches, watch);
+  watched_fd_add_select (watched_fd);
+  return (watch);
+}
+
+
+/*
+ * 'watch_free' - Free a file descriptor watch
+ */
+
+static void
+watch_free (AvahiWatch *watch)
+{
+  cupsd_watched_fd_t *watched_fd = watch->watched_fd;
+  AvahiCupsPoll *cups_poll = watched_fd->cups_poll;
+
+  cupsArrayRemove (watched_fd->watches, watch);
+  free (watch);
+
+  if (!watched_fd_add_select (watched_fd)) {
+    /* No more watches */
+    cupsArrayRemove (cups_poll->watched_fds, watched_fd);
+    free (watched_fd);
+  }
+}
+
+
+/*
+ * 'watch_update' - Update watched events for a file descriptor
+ */
+
+static void
+watch_update (AvahiWatch *watch,
+	      AvahiWatchEvent events)
+{
+  watch->events = events;
+  watched_fd_add_select (watch->watched_fd);
+}
+
+
+/*
+ * 'watch_get_events' - Get events that happened for a file descriptor
+ */
+
+static AvahiWatchEvent
+watch_get_events (AvahiWatch *watch)
+{
+  return (watch->watched_fd->occurred);
+}
+
+
+/*
+ * 'compare_watches' - Compare watches for array sorting
+ */
+
+static int
+compare_watches (AvahiWatch *p0,
+		 AvahiWatch *p1)
+{
+  if (p0->watched_fd->fd < p1->watched_fd->fd)
+    return (-1);
+
+  return ((p0->watched_fd->fd == p1->watched_fd->fd) ? 0 : 1);
+}
+
+
+/*
+ * 'timeout_cb()' - Run a timed Avahi callback
+ */
+
+static void
+timeout_cb (cupsd_timeout_t *cupsd_timeout, void *userdata)
+{
+  AvahiTimeout *timeout = userdata;
+  (timeout->callback) (timeout, timeout->userdata);
+}
+
+
+/*
+ * 'timeout_new' - Set a wakeup time
+ */
+
+static AvahiTimeout *
+timeout_new (const AvahiPoll *api,
+	     const struct timeval *tv,
+	     AvahiTimeoutCallback callback,
+	     void *userdata)
+{
+  AvahiTimeout *timeout;
+  AvahiCupsPoll *cups_poll = api->userdata;
+
+  timeout = malloc(sizeof(AvahiTimeout));
+  if (timeout == NULL)
+    return (NULL);
+
+  timeout->cups_poll = cups_poll;
+  timeout->callback = callback;
+  timeout->userdata = userdata;
+  timeout->cupsd_timeout = cupsdAddTimeout (tv,
+					    (cupsd_timeoutfunc_t)timeout_cb,
+					    timeout);
+  cupsArrayAdd (cups_poll->timeouts, timeout);
+  return (timeout);
+}
+
+
+/*
+ * 'timeout_update' - Update the expiration time for a timeout
+ */
+
+static void
+timeout_update (AvahiTimeout *timeout,
+		const struct timeval *tv)
+{
+  cupsdUpdateTimeout (timeout->cupsd_timeout, tv);
+}
+
+
+/*
+ * ' timeout_free' - Free a timeout
+ */
+
+static void
+timeout_free (AvahiTimeout *timeout)
+{
+  cupsArrayRemove (timeout->cups_poll->timeouts, timeout);
+  cupsdRemoveTimeout (timeout->cupsd_timeout);
+  free (timeout);
+}
+
+
+/*
+ * 'compare_watched_fds' - Compare watched file descriptors for array sorting
+ */
+static int
+compare_watched_fds(cupsd_watched_fd_t *p0,
+		    cupsd_watched_fd_t *p1)
+{
+  if (p0->fd != p1->fd)
+    return (p0->fd < p1->fd ? -1 : 1);
+
+  if (p0 == p1)
+    return (0);
+
+  return (p0 < p1 ? -1 : 1);
+}
+
+
+/*
+ * 'compare_timeouts' - Compare timeouts for array sorting
+ */
+static int
+compare_timeouts(AvahiTimeout *p0,
+		 AvahiTimeout *p1)
+{
+ /*
+  * Just compare pointers to make it a stable sort.
+  */
+
+  if (p0->cupsd_timeout < p1->cupsd_timeout)
+    return (-1);
+  return ((p0->cupsd_timeout == p1->cupsd_timeout) ? 0 : 1);
+}
+
+
+/*
+ * 'avahi_cups_poll_new' - Create a new Avahi main loop object for CUPS
+ */
+
+AvahiCupsPoll *
+avahi_cups_poll_new (void)
+{
+  AvahiCupsPoll *cups_poll = malloc(sizeof(AvahiCupsPoll));
+  if (cups_poll == NULL)
+    return (NULL);
+
+  cups_poll->watched_fds = cupsArrayNew ((cups_array_func_t)compare_watched_fds,
+					 NULL);
+  cups_poll->timeouts = cupsArrayNew ((cups_array_func_t)compare_timeouts,
+				      NULL);
+
+  cups_poll->api.userdata = cups_poll;
+  cups_poll->api.watch_new = watch_new;
+  cups_poll->api.watch_free = watch_free;
+  cups_poll->api.watch_update = watch_update;
+  cups_poll->api.watch_get_events = watch_get_events;
+
+  cups_poll->api.timeout_new = timeout_new;
+  cups_poll->api.timeout_update = timeout_update;
+  cups_poll->api.timeout_free = timeout_free;
+
+  return (cups_poll);
+}
+
+
+/*
+ * 'avahi_cups_poll_free' - Free an Avahi main loop object for CUPS
+ */
+void
+avahi_cups_poll_free (AvahiCupsPoll *cups_poll)
+{
+  cupsd_watched_fd_t *watched_fd;
+
+  for (watched_fd = (cupsd_watched_fd_t*)cupsArrayFirst(cups_poll->watched_fds);
+       watched_fd;
+       watched_fd = (cupsd_watched_fd_t*)cupsArrayNext(cups_poll->watched_fds)){
+    cupsArrayClear (watched_fd->watches);
+  }
+
+  cupsArrayClear (cups_poll->watched_fds);
+  cupsArrayClear (cups_poll->timeouts);
+}
+
+
+/*
+ * 'avahi_cups_poll_get' - Get the abstract poll API structure
+ */
+
+const AvahiPoll *
+avahi_cups_poll_get (AvahiCupsPoll *cups_poll)
+{
+  return (&cups_poll->api);
+}
+
+
+#endif /* HAVE_AVAHI ... from top of file */
+
+/*
+ * End of "$Id$".
+ */
diff -up cups-1.4.7/scheduler/avahi.h.avahi-4-poll cups-1.4.7/scheduler/avahi.h
--- cups-1.4.7/scheduler/avahi.h.avahi-4-poll	2011-06-28 12:54:34.658228283 +0100
+++ cups-1.4.7/scheduler/avahi.h	2011-06-28 12:54:34.658228283 +0100
@@ -0,0 +1,49 @@
+/*
+ * "$Id$"
+ *
+ *   Avahi poll implementation for the CUPS scheduler.
+ *
+ *   Copyright (C) 2010 Red Hat, Inc.
+ *   Authors:
+ *    Tim Waugh <twaugh@redhat.com>
+ *
+ *   Distribution and use rights are outlined in the file "LICENSE.txt"
+ *   which should have been included with this file.  If this file is
+ *   file is missing or damaged, see the license at "http://www.cups.org/".
+ */
+
+#include <config.h>
+
+#ifdef HAVE_AVAHI
+#  include <avahi-client/client.h>
+#  include <avahi-client/publish.h>
+#endif /* HAVE_AVAHI */
+
+#ifdef HAVE_AUTHORIZATION_H
+#  include <Security/Authorization.h>
+#endif /* HAVE_AUTHORIZATION_H */
+
+
+#ifdef HAVE_AVAHI
+typedef struct
+{
+    AvahiPoll api;
+    cups_array_t *watched_fds;
+    cups_array_t *timeouts;
+} AvahiCupsPoll;
+#endif /* HAVE_AVAHI */
+
+/*
+ * Prototypes...
+ */
+
+#ifdef HAVE_AVAHI
+extern AvahiCupsPoll *	avahi_cups_poll_new(void);
+extern void		avahi_cups_poll_free(AvahiCupsPoll *cups_poll);
+extern const AvahiPoll *avahi_cups_poll_get(AvahiCupsPoll *cups_poll);
+#endif /* HAVE_AVAHI */
+
+
+/*
+ * End of "$Id$".
+ */
diff -up cups-1.4.7/scheduler/Makefile.avahi-4-poll cups-1.4.7/scheduler/Makefile
--- cups-1.4.7/scheduler/Makefile.avahi-4-poll	2011-06-28 12:54:06.906728322 +0100
+++ cups-1.4.7/scheduler/Makefile	2011-06-28 12:54:34.651228409 +0100
@@ -17,6 +17,7 @@ include ../Makedefs
 
 CUPSDOBJS =	\
 		auth.o \
+		avahi.o \
 		banners.o \
 		cert.o \
 		classes.o \