[Groff] trace.tmac and backslashes

[Werner LEMBERG]

I've just added the following snippet to groff_trace.tmac:

  PROBLEMS
       Because trace.tmac wraps the .de request (and its cousins), macro argu-
       ments are expanded one level more.  This causes problems if an argument
       contains four backslashes or more to prevent too early expansion of the
       backslash.  For example, this macro call

       .foo \\\\n[bar]

       normally  passes `\\n[bar]' to macro `.foo', but with the redefined .de
       request it passes `\n[bar]' instead.

       The solution to this problem is to use groff's \E escape  which  is  an
       escape character not interpreted in copy mode, for example

       .foo \En[bar]



   Werner