Add multiple inheritance to keymaps.

* src/keymap.c (Fmake_composed_keymap): New function.
(Fset_keymap_parent): Simplify.
(fix_submap_inheritance): Remove.
(access_keymap_1): New function extracted from access_keymap to handle
embedded parents and handle lists of maps.
(access_keymap): Use it.
(Fkeymap_prompt, map_keymap_internal, map_keymap, store_in_keymap)
(Fcopy_keymap): Handle embedded parents.
(Fcommand_remapping, define_as_prefix): Simplify.
(Fkey_binding): Simplify.
(syms_of_keymap): Move minibuffer-local-completion-map,
minibuffer-local-filename-completion-map,
minibuffer-local-must-match-map, and
minibuffer-local-filename-must-match-map to Elisp.
(syms_of_keymap): Defsubr make-composed-keymap.
* src/keyboard.c (menu_bar_items): Use map_keymap_canonical.
(parse_menu_item): Trivial simplification.
* lisp/subr.el (remq): Don't allocate if it's not needed.
(keymap--menu-item-binding, keymap--menu-item-with-binding)
(keymap--merge-bindings): New functions.
(keymap-canonicalize): Use them to refine the canonicalization.
* lisp/minibuffer.el (minibuffer-local-completion-map)
(minibuffer-local-must-match-map): Move initialization from C.
(minibuffer-local-filename-completion-map): Move initialization from C;
don't inherit from anything here.
(minibuffer-local-filename-must-match-map): Make obsolete.
(completing-read-default): Use make-composed-keymap to combine
minibuffer-local-filename-completion-map with either
minibuffer-local-must-match-map or
minibuffer-local-filename-completion-map.

1 files changed, 5 insertions, 0 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 5cf4cd1b7cf..01b767b62f7 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -111,6 +111,10 @@ and pops down the *Completions* buffer accordingly.
 *** `completing-read' can be customized using the new variable
 `completing-read-function'.
 
+*** minibuffer-local-filename-must-match-map is not used any more.
+Instead, the bindings in minibuffer-local-filename-completion-map are combined
+with minibuffer-local-must-match-map.
+
 ** auto-mode-case-fold is now enabled by default.
 
 ** smtpmail changes
@@ -1094,6 +1098,7 @@ as well as those in the -*- line.
 ---
 ** rx.el has a new `group-n' construct for explicitly numbered groups.
 
+** keymaps can inherit from multiple parents.
 
 * Changes in Emacs 24.1 on non-free operating systems