emacs-30 e281355a5e8 1/2: Improve D-Bus and Tramp manual

[Michael Albinus]

branch: emacs-30
commit e281355a5e88771b66afe35f425ce09064ef5147
Author: Michael Albinus <michael.albinus@gmx.de>
Commit: Michael Albinus <michael.albinus@gmx.de>

    Improve D-Bus and Tramp manual
    
    * doc/misc/dbus.texi (Overview):
    * doc/misc/tramp.texi (GVFS-based methods): Describe, how the
    feature can be checked at runtime.  (Bug#75004)
---
 doc/misc/dbus.texi  | 9 ++++++---
 doc/misc/tramp.texi | 9 ++++++---
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/doc/misc/dbus.texi b/doc/misc/dbus.texi
index 4d46564944f..1020e027774 100644
--- a/doc/misc/dbus.texi
+++ b/doc/misc/dbus.texi
@@ -75,9 +75,12 @@ another.  An overview of D-Bus can be found at
 @cindex overview
 
 D-Bus is an inter-process communication mechanism for applications
-residing on the same host.  The communication is based on
-@dfn{messages}.  Data in the messages is carried in a structured way,
-it is not just a byte stream.
+residing on the same host.  Emacs uses it when it is compiled with the
+respective library, see configuration option @option{--with-dbus}.  At
+runtime, the form @code{(featurep 'dbusbind)} indicates D-Bus support.
+
+D-Bus communication is based on @dfn{messages}.  Data in the messages is
+carried in a structured way, it is not just a byte stream.
 
 The communication is connection oriented to two kinds of message
 buses: a so called @dfn{system bus}, and a @dfn{session bus}.  On a
diff --git a/doc/misc/tramp.texi b/doc/misc/tramp.texi
index 94e06ce6af3..b98b9b1fe5c 100644
--- a/doc/misc/tramp.texi
+++ b/doc/misc/tramp.texi
@@ -1365,9 +1365,12 @@ Desktop, @uref{https://en.wikipedia.org/wiki/GVFS}.  
Remote files on
 @acronym{GVFS} are mounted locally through @acronym{FUSE} and
 @value{tramp} uses this locally mounted directory internally.
 
-Emacs uses the D-Bus mechanism to communicate with @acronym{GVFS}@.
-Emacs must have the message bus system, D-Bus integration active,
-@pxref{Top, , D-Bus, dbus}.
+Emacs uses the D-Bus mechanism to communicate with @acronym{GVFS}@.  It
+must have been compiled with D-Bus support, @pxref{Top, , D-Bus, dbus}.
+
+@vindex tramp-gvfs-enabled
+The @code{tramp-gvfs-enabled} variable, being non-@code{nil}, signals
+that @value{tramp} can use @acronym{GVFS}-based methods.
 
 @table @asis
 @cindex method @option{afp}