Add basic D-Bus integration to Gnus

* lisp/gnus/gnus-dbus.el: New library, registering a signal that
closes all Gnus servers when the system is going to sleep.
* lisp/gnus/gnus-start.el: Check new option
`gnus-dbus-close-on-sleep', and register the appropriate D-Bus signal
if it is non-nil.
* lisp/gnus/gnus.el: New gnus-dbus customization group.
* doc/misc/gnus.texi: Document.

1 files changed, 22 insertions, 0 deletions

diff --git a/doc/misc/gnus.texi b/doc/misc/gnus.texi
index 332926a6859..0bdc2fa297d 100644
--- a/doc/misc/gnus.texi
+++ b/doc/misc/gnus.texi
@@ -828,6 +828,7 @@ Various
 * Spam Package::                A package for filtering and processing spam.
 * The Gnus Registry::           A package for tracking messages by Message-ID.
 * The Gnus Cloud::              A package for synchronizing Gnus marks.
+* D-Bus Integration::           Closing Gnus servers on system sleep.
 * Other modes::                 Interaction with other modes.
 * Various Various::             Things that are really various.
 
@@ -22333,6 +22334,7 @@ to you, using @kbd{G b u} and updating the group will usually fix this.
 * Spam Package::                A package for filtering and processing spam.
 * The Gnus Registry::           A package for tracking messages by Message-ID.
 * The Gnus Cloud::              A package for synchronizing Gnus marks.
+* D-Bus Integration::           Closing Gnus servers on system sleep.
 * Other modes::                 Interaction with other modes.
 * Various Various::             Things that are really various.
 @end menu
@@ -26404,6 +26406,26 @@ CloudSynchronizationDataPack(TM)s. It's easiest to set this from the
 Server buffer (@pxref{Gnus Cloud Setup}).
 @end defvar
 
+@node D-Bus Integration
+@section D-Bus Integration
+@cindex dbus
+@cindex D-Bus
+@cindex gnus-dbus
+@cindex system sleep
+@cindex closing servers automatically
+@cindex hung connections
+
+When using laptops or other systems that have a sleep or hibernate
+functionality, it's possible for long-running server connections to
+become ``hung'', requiring the user to manually close and re-open the
+connections after the system resumes.  On systems compiled with D-Bus
+support (check the value of @code{(featurep 'dbusbind)}), Gnus can
+register a D-Bus signal to automatically close all server connections
+before the system goes to sleep.  To enable this, set
+@code{gnus-dbus-close-on-sleep} to a non-nil value.
+
+For more information about D-Bus and Emacs, @pxref{Top,,, dbus, D-Bus integration in Emacs}.
+
 @node Other modes
 @section Interaction with other modes