Translate describe_map_tree to Lisp

This is the second step in converting substitute-command-keys to Lisp.

* lisp/help.el (describe-map-tree): New Lisp version of
describe_map_tree.
(substitute-command-keys): Update to use above function.
* src/keymap.c (Fdescribe_map): New defun to expose describe_map to
Lisp.
* src/keymap.c (syms_of_keymap): New variable 'help--keymaps-seen'; a
temporary kludge planned for removal.  New defsubr for Fdescribe_map.

1 files changed, 28 insertions, 2 deletions

diff --git a/src/keymap.c b/src/keymap.c
index 05b0814c475..704b89eeecc 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -2915,7 +2915,7 @@ You type        Translation\n\
 
    Any inserted text ends in two newlines (used by `help-make-xrefs').  */
 
-DEFUN ("describe-map-tree", Fdescribe_map_tree, Sdescribe_map_tree, 1, 8, 0,
+DEFUN ("describe-map-tree-old", Fdescribe_map_tree_old, Sdescribe_map_tree_old, 1, 8, 0,
        doc: /* This is just temporary.  */)
   (Lisp_Object startmap, Lisp_Object partial, Lisp_Object shadow,
    Lisp_Object prefix, Lisp_Object title, Lisp_Object nomenu,
@@ -3131,6 +3131,27 @@ describe_map_compare (const void *aa, const void *bb)
   return 0;
 }
 
+DEFUN ("describe-map", Fdescribe_map, Sdescribe_map, 1, 7, 0,
+       doc: /* This is a temporary definition preparing the transition
+of this function to Lisp.  */)
+  (Lisp_Object map, Lisp_Object prefix,
+   Lisp_Object transl, Lisp_Object partial, Lisp_Object shadow,
+   Lisp_Object nomenu, Lisp_Object mention_shadow)
+{
+  ptrdiff_t count = SPECPDL_INDEX ();
+
+  bool b_transl = NILP(transl) ? false : true;
+  bool b_partial = NILP (partial) ? false : true;
+  bool b_nomenu = NILP (nomenu) ? false : true;
+  bool b_mention_shadow = NILP (mention_shadow) ? false : true;
+  describe_map (map, prefix,
+                b_transl ? describe_translation : describe_command,
+                b_partial, shadow, &Vhelp__keymaps_seen,
+                b_nomenu, b_mention_shadow);
+
+  return unbind_to (count, Qnil);
+}
+
 /* Describe the contents of map MAP, assuming that this map itself is
    reached by the sequence of prefix keys PREFIX (a string or vector).
    PARTIAL, SHADOW, NOMENU are as in `describe_map_tree' above.  */
@@ -3685,6 +3706,10 @@ exists, bindings using keys without modifiers (or only with meta) will
 be preferred.  */);
   Vwhere_is_preferred_modifier = Qnil;
   where_is_preferred_modifier = 0;
+  DEFVAR_LISP ("help--keymaps-seen", Vhelp__keymaps_seen,
+               doc: /* List of seen keymaps.
+This is used for internal purposes only.  */);
+  Vhelp__keymaps_seen = Qnil;
 
   DEFSYM (Qmenu_bar, "menu-bar");
   DEFSYM (Qmode_line, "mode-line");
@@ -3739,7 +3764,8 @@ be preferred.  */);
   defsubr (&Scurrent_active_maps);
   defsubr (&Saccessible_keymaps);
   defsubr (&Skey_description);
-  defsubr (&Sdescribe_map_tree);
+  defsubr (&Sdescribe_map_tree_old);
+  defsubr (&Sdescribe_map);
   defsubr (&Sdescribe_vector);
   defsubr (&Ssingle_key_description);
   defsubr (&Stext_char_description);