Implement the roff(7) .rn (rename macro or string) request.

Renaming a user-defined macro is very simple: just copy
the definition to the new name and delete the old name.
Renaming high-level macros is a bit tricky: use a dedicated
key-value-table, with non-standard names as keys and standard
names as values.  When a macro is found that is not user-defined,
look it up in the "renamed" table and translate it back to the
standard name before passing it on to the high-level parsers.

1 files changed, 13 insertions, 4 deletions

diff --git a/roff.7 b/roff.7
index 7d3465ac..decc9d94 100644
--- a/roff.7
+++ b/roff.7
@@ -1,4 +1,4 @@
-.\"	$Id: roff.7,v 1.85 2017/06/06 15:03:35 schwarze Exp $
+.\"	$Id: roff.7,v 1.86 2017/06/07 00:50:34 schwarze Exp $
 .\"
 .\" Copyright (c) 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
 .\" Copyright (c) 2010,2011,2013-2015,2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: June 6 2017 $
+.Dd $Mdocdate: June 7 2017 $
 .Dt ROFF 7
 .Os
 .Sh NAME
@@ -530,7 +530,7 @@ input lines without filling.
 .Ar N
 defaults to 1.
 An argument of 0 or less ends centering.
-Currently, high level macros abort certering.
+Currently, high level macros abort centering.
 .It Ic \&cf Ar filename
 Output the contents of a file.
 Ignored because insecure.
@@ -1482,7 +1482,16 @@ Currently ignored.
 Remove a request, macro or string.
 .It Ic \&rn Ar oldname newname
 Rename a request, macro, diversion, or string.
-Currently unsupported.
+In
+.Xr mandoc 1 ,
+user-defined macros,
+.Xr mdoc 7
+and
+.Xr man 7
+macros, and user-defined strings can be renamed, but renaming of
+predefined strings and of
+.Nm
+requests is not supported, and diversions are not implemented at all.
 .It Ic \&rnn Ar oldname newname
 Rename a number register.
 Currently unsupported.