Update for tgetstr() null areas.

lib/libterm/termcap.3

@@ -1,4 +1,4 @@
-.\"	$NetBSD: termcap.3,v 1.31 2005/05/15 21:11:13 christos Exp $
+.\"	$NetBSD: termcap.3,v 1.32 2006/12/18 13:27:25 kleink Exp $
 .\"
 .\" Copyright (c) 1980, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -29,7 +29,7 @@
 .\"
 .\"     @(#)termcap.3	8.2 (Berkeley) 12/11/93
 .\"
-.Dd May 15, 2005
+.Dd December 17, 2006
 .Dt TERMCAP 3
 .Os
 .Sh NAME
@@ -189,12 +189,18 @@ The
 .Fn tgetstr
 function
 returns the string value of the capability
-.Fa id ,
-places it in the buffer at
-.Fa area ,
-and advances the
+.Fa id ;
+if
 .Fa area
-pointer.
+does not point to
+.Dv NULL
+and does not point to a pointer to
+.Dv NULL ,
+it copies the string value into the buffer pointed to by
+.Fa *area ,
+and advances the
+.Fa *area
+pointer past the copy of the string.
 It decodes the abbreviations for this field described in
 .Xr termcap 5 ,
 except for cursor addressing and padding information.