IDO: Disable match re-ordering for buffer switching

Fixes: debbugs:2042

2 files changed, 26 insertions, 2 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index e8a05696437..8134363f184 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2012-09-16  Leo Liu  <sdl.web@gmail.com>
+
+        IDO: Disable match re-ordering for buffer switching.
+        * ido.el (ido-confirm-unique-completion): New variable.
+        (ido-set-matches-1): Use it.  (Bug#2042)
+
 2012-09-12  Jose Marino  <marinoj@nso.edu>  (tiny change)
 
         * progmodes/idlw-shell.el (idlwave-shell-complete-filename):
diff --git a/lisp/ido.el b/lisp/ido.el
index fe94c7f225e..512ac9d4a18 100644
--- a/lisp/ido.el
+++ b/lisp/ido.el
@@ -493,6 +493,17 @@ as first char even if `ido-enable-prefix' is nil."
   :type 'boolean
   :group 'ido)
 
+;; See http://debbugs.gnu.org/2042 for more info.
+(defcustom ido-buffer-disable-smart-matches t
+  "Non-nil means not to re-order matches for buffer switching.
+By default, ido aranges matches in the following order:
+
+  full-matches > suffix matches > prefix matches > remaining matches
+
+which can get in the way for buffer switching."
+  :type 'boolean
+  :group 'ido)
+
 (defcustom ido-confirm-unique-completion nil
   "Non-nil means that even a unique completion must be confirmed.
 This means that \\[ido-complete] must always be followed by \\[ido-exit-minibuffer]
@@ -3688,10 +3699,17 @@ This is to make them appear as if they were \"virtual buffers\"."
          (rex0 (if ido-enable-regexp text (regexp-quote text)))
          (rexq (concat rex0 (if slash ".*/" "")))
          (re (if ido-enable-prefix (concat "\\`" rexq) rexq))
-         (full-re (and do-full (not ido-enable-regexp) (not (string-match "\$\\'" rex0))
+         (full-re (and do-full
+                       (and (eq ido-cur-item 'buffer)
+                            (not ido-buffer-disable-smart-matches))
+                       (not ido-enable-regexp)
+                       (not (string-match "\$\\'" rex0))
                        (concat "\\`" rex0 (if slash "/" "") "\\'")))
          (suffix-re (and do-full slash
-                         (not ido-enable-regexp) (not (string-match "\$\\'" rex0))
+                         (and (eq ido-cur-item 'buffer)
+                              (not ido-buffer-disable-smart-matches))
+                         (not ido-enable-regexp)
+                         (not (string-match "\$\\'" rex0))
                          (concat rex0 "/\\'")))
          (prefix-re (and full-re (not ido-enable-prefix)
                          (concat "\\`" rexq)))