1 files changed, 13 insertions, 3 deletions
diff --git a/doc/lispref/files.texi b/doc/lispref/files.texi
index b071c6a8f35..ac77b94d8f6 100644
--- a/doc/lispref/files.texi
+++ b/doc/lispref/files.texi
@@ -714,15 +714,15 @@ some other job.
 This function locks the file @var{filename}, if the current buffer is
 modified.  The argument @var{filename} defaults to the current buffer's
 visited file.  Nothing is done if the current buffer is not visiting a
-file, or is not modified, or if the system does not support locking.
+file, or is not modified, or if the option @code{create-lockfiles} is
+@code{nil}.
 @end defun
 
 @defun unlock-buffer
 This function unlocks the file being visited in the current buffer,
 if the buffer is modified.  If the buffer is not modified, then
 the file should not be locked, so this function does nothing.  It also
-does nothing if the current buffer is not visiting a file, or if the
-system does not support locking.
+does nothing if the current buffer is not visiting a file, or is not locked.
 @end defun
 
 @defopt create-lockfiles
@@ -1693,6 +1693,16 @@ version of an existing file; saving a file preserves its existing
 permissions.
 @end defun
 
+@defmac with-file-modes mode body@dots{}
+This macro evaluates the @var{body} forms with the default
+permissions for new files temporarily set to @var{modes} (whose value
+is as for @code{set-file-modes} above).  When finished, it restores
+the original default file permissions, and returns the value of the
+last form in @var{body}.
+
+This is useful for creating private files, for example.
+@end defmac
+
 @defun default-file-modes
 This function returns the default file permissions, as an integer.
 @end defun