[RFA] use filename_completer for add_setshow_optional_filename_cmd

["Pierre Muller" <muller@ics.u-strasbg.fr>]

  I discovered that
set debug-file-directory does not use filename_completer.

  This is because add_setshow_optional_filename_cmd
does not set the set completer to filename completer,
contrary to add_setshow_filename_cmd.
  
  Is there any reason for this?
Or is it just a bug?

  The following small patch fixes this
by setting the set part completer to filename_completer
for  add_setshow_optional_filename_cmd
exactly as is done in add_setshow_filename_cmd.
  
  There are currently only three adffected commands:

"set debug-file-directory"
"set args"
"set solib-search-path"

  Only the second one might be questionable,
but I also find that it is reasonable to have filename
completion for "set args" as this is now done on
most shells.

  I ran the testsuite with that patch on cygwin,
and the only difference I got was in gdb.trace/packetlen.exp
but I can't see any relation with the patch, and this
problem is probably due to some instabilities on
the cygwin testsuite. 

Is this OK to commit?


Pierre Muller

Pascal language support maintainer for GDB

ChangeLog entry:

2008-07-01  Pierre Muller  <muller@ics.u-strasbg.fr>

	cli/cli-decode.c (add_setshow_optional_filename_cmd): Set
	completer for set to filename_completer.


Index: gdb/cli/cli-decode.c
===================================================================
RCS file: /cvs/src/src/gdb/cli/cli-decode.c,v
retrieving revision 1.65
diff -u -p -r1.65 cli-decode.c
--- gdb/cli/cli-decode.c        3 May 2008 23:24:17 -0000       1.65
+++ gdb/cli/cli-decode.c        1 Jul 2008 15:27:41 -0000
@@ -539,11 +539,16 @@ add_setshow_optional_filename_cmd (char
                                   struct cmd_list_element **set_list,
                                   struct cmd_list_element **show_list)
 {
+  struct cmd_list_element *set_result;
+
   add_setshow_cmd_full (name, class, var_optional_filename, var,
                        set_doc, show_doc, help_doc,
                        set_func, show_func,
                        set_list, show_list,
-                       NULL, NULL);
+                       &set_result, NULL);
+
+  set_cmd_completer (set_result, filename_completer);
+
 }

 /* Add element named NAME to both the set and show command LISTs (the