David, here is the updated patch based on your suggestion.  It is definitely 
cleaner in the short-term.

2003-12-09  Jeff Johnston  <jjohnstn@redhat.com>

     * linespec.h (decode_line_1): Add new not_found_ptr parameter.
     * linespec.c (decode_line_1): Add new parameter.  Pass on
     new parameter to decode_variable and symtab_from_filename
     functions.
     (decode_variable): Add new not_found_ptr parameter.  Throw exception
     rather than failing if the not_found_ptr is non-null and the
     function is not found.
     (symtab_from_filename): Add new not_found_ptr parametr.   Throw exception
     rather than failing if the not_found_ptr is non-null and the
     source file is not found.
     * breakpoint.c: Change all callers of decode_line_1 to add default
     extra parameter for decode_line_1 calls.
     * tracepoint.c: Ditto.
     * cli/cli-cmds.c: Ditto.

David Carlton wrote:
> On Mon, 08 Dec 2003 17:49:50 -0500, "J. Johnston" <jjohnstn@redhat.com> said:
> 
>>David Carlton wrote:
> 
> 
>>>A unit test would be nice, too, if possible.
> 
> 
>>Well, that comes with my pending breakpoint support which I was
>>asked to break into smaller chunks and get the support structure in
>>place first.  It will be the first and perhaps only user of this
>>functionality.
> 
> 
> Fair enough.
> 
> David Carlton
> carlton@kealia.com
>