(non-essential): New var.

2 files changed, 10 insertions, 0 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b9e8ea511e6..f2330b0763c 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,7 @@
 2010-04-14  Stefan Monnier  <monnier@iro.umontreal.ca>
 
+        * simple.el (non-essential): New var.
+
         Add a new field `location' to bookmarks for non-file bookmarks.
         * bookmark.el (bookmark-location): Use the new field, if present.
         (bookmark-insert-location): Undo last change, not needed any more.
diff --git a/lisp/simple.el b/lisp/simple.el
index 34e31b10276..d071c76e2b1 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -3940,6 +3940,14 @@ the current accessible part of the buffer.
 If `widen-automatically' is nil, these commands will do something else
 as a fallback, and won't change the buffer bounds.")
 
+(defvar non-essential nil
+  "Whether the currently executing code is performing an essential task.
+This variable should be non-nil only when running code which should not
+disturb the user.  E.g. it can be used to prevent Tramp from prompting the
+user for a password when we are simply scanning a set of files in the
+background or displaying possible completions before the user even asked
+for it.")
+
 (defun pop-global-mark ()
   "Pop off global mark ring and jump to the top location."
   (interactive)