* doc/misc/dbus.texi (Synchronous Methods): Adapt `dbus-call-method'.
(Asynchronous Methods): Adapt `dbus-call-method-asynchronously'.
(File Descriptors): New chapter, replaces Inhibitor Locks.

* etc/NEWS: Replace "New D-Bus functions to support systemd
inhibitor locks" by "Support D-Bus file descriptor manipulation".
Presentational fixes and improvements.

* lisp/net/dbus.el (dbus-call-method)
(dbus-call-method-asynchronously): Adapt docstring.
(dbus-list-hash-table): Return (nreverse result).
(dbus-monitor-goto-serial): Declare `completion'.

* src/dbusbind.c (Fdbus_message_internal, xd_read_message_1):
Handle `:keep-fd'.
(xd_registered_inhibitor_locks, Fdbus_make_inhibitor_lock)
(Fdbus_close_inhibitor_lock, Fdbus_registered_inhibitor_locks): Delete.
(xd_registered_fds): New variable.
(Fdbus__fd_open, Fdbus__fd_close, Fdbus__registered_fds):
New DEFUNs.  (Bug#79963)
(syms_of_dbusbind_for_pdumper): Initialize `xd_registered_fds'.
(syms_of_dbusbind): Remove subroutines
`Sdbus_make_inhibitor_lock', `Sdbus_close_inhibitor_lock' and
`Sdbus_registered_inhibitor_locks'.  Remove symbol `Qdbus_call_method'.
Declare subroutines `Sdbus__fd_open', `Sdbus__fd_close' and
`Sdbus__registered_fds'.  Declare symbol `QCkeep_fd'.  staticpro
`xd_registered_fds'.

* test/lisp/net/dbus-tests.el (dbus-test10-inhibitor-locks): Delete.
(dbus-test10-keep-fd, dbus-test10-open-close-fd): New tests.

* doc/misc/dbus.texi (Top): Add "Inhibitor Locks" submenu.
Remove trailing period from chapter and section titles.
(Inhibitor Locks): New node.

* etc/NEWS: New D-Bus functions to support systemd inhibitor locks.
Presentational fixes and improvements.

* src/dbusbind.c (xd_registered_inhibitor_locks): New variable.
(Fdbus_make_inhibitor_lock, Fdbus_close_inhibitor_lock)
(Fdbus_registered_inhibitor_locks): New DEFUNs.  (Bug#79963)
(syms_of_dbusbind_for_pdumper): Initialize
`xd_registered_inhibitor_locks'.
(syms_of_dbusbind): Declare subroutines
`Sdbus_make_inhibitor_lock', `Sdbus_close_inhibitor_lock' and
`Sdbus_registered_inhibitor_locks'.  Declare symbol `Qdbus_call_method'.
staticpro `xd_registered_inhibitor_locks'.

* test/lisp/net/dbus-tests.el (dbus--test-systemd-service)
(dbus--test-systemd-path, dbus--test-systemd-manager-interface):
New defconsts.
(dbus-test10-inhibitor-locks): New test.

* doc/misc/dbus.texi (Signals): All registered signal handlers are
called.
(Synchronous Methods, Signals, Monitoring Messages): Add function
result in examples.

* src/dbusbind.c (xd_store_event): New function.
(xd_read_message_1): Use it.  Call all registered handlers per
signal.  (Bug#80168)

* test/lisp/net/dbus-tests.el (dbus--test-signal-handler): Adapt defun.
(dbus--test-signal-handler1, dbus--test-signal-handler2): New defuns.
(dbus-test05-register-signal-several-handlers): New test.
(dbus-test04-register-method)
(dbus-test04-call-method-authorizable)
(dbus-test05-register-signal)
(dbus-test05-register-signal-with-nils)
(dbus-test06-register-property-emits-signal): Adapt tests.

* src/dbusbind.c (XD_DBUS_VALIDATE_BUS_NAME)
(XD_DBUS_VALIDATE_PATH, XD_DBUS_VALIDATE_INTERFACE)
(XD_DBUS_VALIDATE_MEMBER): Make these expand to single statements
when they are followed by ‘;’.  All uses changed.