commit af597f1103f4c20d02c90d775742130c4b349d1b
Author: Sam Thursfield <sam.thursfield@codethink.co.uk>
Date:   Mon Jun 18 12:36:37 2012 +0100

    libudev: Fix documentation for udev_monitor_receive_device()

diff --git a/src/libudev/libudev-monitor.c b/src/libudev/libudev-monitor.c
index 32319ac..aa6dbe9 100644
--- a/src/libudev/libudev-monitor.c
+++ b/src/libudev/libudev-monitor.c
@@ -489,15 +489,22 @@ tag:
  * udev_monitor_receive_device:
  * @udev_monitor: udev monitor
  *
- * Receive data from the udev monitor socket, allocate a new udev
- * device, fill in the received data, and return the device.
+ * Receive data from the udev monitor socket, allocate a
+ * new udev device, fill in the received data, and return the device.
+ *
+ * It is an error to call this function if there is no data available.
+ * The function will return #NULL in this case. You should monitor the
+ * file handle returned by udev_monitor_get_fd() to ensure data is available
+ * before calling. Note that the behaviour of this function changed in
+ * libudev 171. Code that assumes this function will block should be changed
+ * to use poll().
  *
  * Only socket connections with uid=0 are accepted.
  *
  * The initial refcount is 1, and needs to be decremented to
  * release the resources of the udev device.
  *
- * Returns: a new udev device, or #NULL, in case of an error
+ * Returns: a new udev device if available, or #NULL
  **/
 _public_ struct udev_device *udev_monitor_receive_device(struct udev_monitor *udev_monitor)
 {