Doc updates for with-demoted-errors

* doc/lispref/control.texi (Handling Errors): Update with-demoted-errors.

* lisp/subr.el (with-demoted-errors): Doc fix.

* etc/NEWS: Related edit.

2 files changed, 7 insertions, 2 deletions

diff --git a/doc/lispref/ChangeLog b/doc/lispref/ChangeLog
index cbbf9127235..6f27e71b7b7 100644
--- a/doc/lispref/ChangeLog
+++ b/doc/lispref/ChangeLog
@@ -1,5 +1,7 @@
 2014-01-24  Glenn Morris  <rgm@gnu.org>
 
+        * control.texi (Handling Errors): Update with-demoted-errors.
+
         * files.texi (File Locks): Every platform supports locking now.
 
 2014-01-22  Glenn Morris  <rgm@gnu.org>
diff --git a/doc/lispref/control.texi b/doc/lispref/control.texi
index 0d6aaff81c5..edf60dd5cc8 100644
--- a/doc/lispref/control.texi
+++ b/doc/lispref/control.texi
@@ -1252,10 +1252,13 @@ Here's the example at the beginning of this subsection rewritten using
 @end example
 @end defmac
 
-@defmac with-demoted-errors body@dots{}
+@defmac with-demoted-errors format body@dots{}
 This macro is like a milder version of @code{ignore-errors}.  Rather
 than suppressing errors altogether, it converts them into messages.
-Use this form around code that is not expected to signal errors, but
+It uses the string @var{format} to format the message.
+@var{format} should contain a single @samp{%}-sequence; e.g.,
+@code{"Error: %S"}.  Use @code{with-demoted-errors} around code
+that is not expected to signal errors, but
 should be robust if one does occur.  Note that this macro uses
 @code{condition-case-unless-debug} rather than @code{condition-case}.
 @end defmac