* tmac/tmac.safer: Will now work correctly in compatibility mode.

3 files changed, 36 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index 102cecbf..91dd5566 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2000-03-09  Werner LEMBERG  <wl@gnu.org>
+
+	* tmac/tmac.safer: Will now work correctly in compatibility mode.
+
 2000-03-08  Werner LEMBERG  <wl@gnu.org>
 
 	* doc/Makefile: Added texput.log to the `clean' target.
diff --git a/doc/groff.texinfo b/doc/groff.texinfo
index 7b4b61b7..94daf819 100644
--- a/doc/groff.texinfo
+++ b/doc/groff.texinfo
@@ -2013,12 +2013,29 @@ expressions, unless the entire expression is surrounded by parentheses.
 @findex ]
 @findex ?
 Like any other language, @code{gtroff} has rules for properly formed
-@dfn{identifiers}.  In @code{gtroff} an identifier can be made up of
-almost any printable character.  The only exception are characters which
-are interpreted by @code{gtroff} (backslash, square brackets, @dots{}).
-So, for example, any of the following is valid.
+@dfn{identifiers}.  In @code{gtroff}, an identifier can be made up of
+almost any printable character.  The exception are the following
+characters:
 
-@c XXX which characters exactly?
+@itemize @bullet
+@item
+Whitespace characters (space, tabs, and newlines).
+@item
+Backspace (@code{0x08}) and character code @code{0x01}.
+@cindex illegal input characters
+@cindex input characters, illegal
+@cindex characters, illegal input
+@item
+The following input characters are illegal and will be ignored, causing
+a warning message: @code{0x00}, @code{0x0B}, @code{0x0D}-@code{0x1F},
+@code{0x80}-@code{0x9F}.
+@end itemize
+
+ @samp{\} (backslash), 
+, and the character codes @code{0x00}@footnote{The null
+character is an invalid character which causes a warning message and
+will be ignored.} and @code{0x01}.  So, for example, any of the
+following is valid.
 
 @example
 br
@@ -2028,6 +2045,12 @@ end-list
 @@_
 @end example
 
+Note that identifiers longer than two characters and containing a
+closing bracket (@samp{]}) can't be accessed with escape sequences which
+expect an identifier as a parameter.
+
+@c XXX xref
+
 @deffn Escape \A ident
 You can test whether an identifier @var{ident} is valid in @code{gtroff}
 with the @code{\A} escape.  It expands to the character@w{ }1 or@w{ }0
@@ -4421,7 +4444,7 @@ name.
 This would be called as
 
 @example
-.vl $Id: groff.texinfo,v 1.17 2000/03/08 11:02:08 wlemb Exp $
+.vl $Id: groff.texinfo,v 1.18 2000/03/09 15:12:10 wlemb Exp $
 @end example
 
 @xref{Request Arguments}.
diff --git a/tmac/tmac.safer b/tmac/tmac.safer
index be348d5f..caabb5bf 100755
--- a/tmac/tmac.safer
+++ b/tmac/tmac.safer
@@ -1,4 +1,6 @@
 .\" remove unsafe requests
+.nr _C \n(.C
+.cp 0
 .rm open opena pso sy pi
 .de unsafe
 .tm \\n(.F:\\n(.c: unsafe to execute request `\\$1'
@@ -8,3 +10,4 @@
 .als pso unsafe
 .als sy unsafe
 .als pi unsafe
+.cp \n(_C