Add a new `inhibit-message' variable

* src/xdisp.c (syms_of_xdisp): Define a boolean `inhibit_message'.
(message3): Don't call `message3_nolog' (i.e. use the Echo Area) when
`inhibit_message' is non-zero.

* etc/NEWS: Add an entry.

* doc/lispref/display.texi: Add an entry for `inhibit-message',
  mention it in `message'.

1 files changed, 7 insertions, 2 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index a17f5a9c34f..6ca190636ec 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -10053,8 +10053,8 @@ message3 (Lisp_Object m)
       message_dolog (buffer, nbytes, true, multibyte);
       SAFE_FREE ();
     }
-  message3_nolog (m);
-
+  if (! inhibit_message)
+    message3_nolog (m);
   UNGCPRO;
 }
 
@@ -30430,6 +30430,11 @@ syms_of_xdisp (void)
 
   DEFSYM (Qredisplay_internal, "redisplay_internal (C function)");
 
+  DEFVAR_BOOL("inhibit-message", inhibit_message,
+              doc:  /* Non-nil means calls to `message' are not displayed.
+They are still logged to the *Messages* buffer.  */);
+  inhibit_message = 0;
+
   message_dolog_marker1 = Fmake_marker ();
   staticpro (&message_dolog_marker1);
   message_dolog_marker2 = Fmake_marker ();