(Old Revisions): Fix diff-switches description.

diff --git a/doc/emacs/ChangeLog b/doc/emacs/ChangeLog
index e38caf2383877ccac43e8f4e0de3faec50a70114..0fa3cf85d958f06f61fc36b37962c6564cc9683b 100644 (file)
--- a/doc/emacs/ChangeLog
+++ b/doc/emacs/ChangeLog
@@ -1,3 +1,7 @@
+2008-12-03  Glenn Morris  <rgm@gnu.org>
+
+       * maintaining.texi (Old Revisions): Fix diff-switches description.
+
 2008-12-01  Martin Rudalics  <rudalics@gmx.at>
 
        * emacs.texi (Top): Fix typo.

diff --git a/doc/emacs/maintaining.texi b/doc/emacs/maintaining.texi
index 220d29c60684817df9bd07afa4a5fe27e002ebbb..ee0f2c51b018c9db8b8cb5c3cb3116a29efb501b 100644 (file)
--- a/doc/emacs/maintaining.texi
+++ b/doc/emacs/maintaining.texi
@@ -707,14 +707,15 @@ current directory and its subdirectories.
 @vindex vc-diff-switches
 @vindex vc-rcs-diff-switches
   @kbd{C-x v =} works by running a variant of the @code{diff} utility
-designed to work with the version control system in use.  When you
-invoke @code{diff} this way, in addition to the options specified by
-@code{diff-switches} (@pxref{Comparing Files}), it receives those
-specified by @code{vc-diff-switches}, plus those specified for the
-specific back end by @code{vc-@var{backend}-diff-switches}.  For
-instance, when the version control back end is CVS, @code{diff} uses
-the options in @code{vc-cvs-diff-switches}.  The
-@samp{vc@dots{}diff-switches} variables are @code{nil} by default.
+designed to work with the version control system in use.  The options
+to pass to the @code{diff} command are taken from the first non-@code{nil}
+value of @code{vc-@var{backend}-diff-switches}, @code{vc-diff-switches},
+and @code{diff-switches} (@pxref{Comparing Files}), in that order.
+Since @code{nil} means to check the next variable in the sequence,
+either of the first two may use the value @code{t} to mean no switches at all.
+The @samp{vc@dots{}diff-switches} variables are all either @code{nil}
+or @code{t} (for those version control systems that do not accept common
+@code{diff} options) by default.
 
   The buffer produced by @kbd{C-x v =} supports the commands of
 Compilation mode (@pxref{Compilation Mode}), such as @kbd{C-x `} and