bug#31783: [PATCH v2] ido.el: define a special ido-fallback variable

[Christophe Junke <junke.christophe@gmail.com>]

- Introduce a global, special ido-fallback variable
- Rename existing occurrences of fallback to ido-fallback

This allows to retain the behaviour that was available prior to
introducing per-file lexical-scope, namely that other modules could
change what fallback command to call when ido-exit is set to
'fallback.
---

Hi,

I agree that it is simpler to rename the existing variable, and just
add a defvar declaration. Here is a different version of the patch
which does only this.

Thank you for your review and your time.

 lisp/ido.el | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/lisp/ido.el b/lisp/ido.el
index 705e7dd630..358e856d4a 100644
--- a/lisp/ido.el
+++ b/lisp/ido.el
@@ -1242,6 +1242,9 @@ Only used if `ido-use-virtual-buffers' is non-nil.")
 ;; Dynamically bound in ido-read-internal.
 (defvar ido-completing-read)
 
+;; Indicates which fallback command to call when ido-exit is 'fallback.
+(defvar ido-fallback nil)
+
 ;;; FUNCTIONS
 
 (defun ido-active (&optional merge)
@@ -2213,13 +2216,13 @@ If cursor is not at the end of the user input, move to end of input."
     (exit-minibuffer)))
 
 ;;; MAIN FUNCTIONS
-(defun ido-buffer-internal (method &optional fallback prompt default initial switch-cmd)
+(defun ido-buffer-internal (method &optional ido-fallback prompt default initial switch-cmd)
   ;; Internal function for ido-switch-buffer and friends
   (if (not ido-mode)
       (progn
 	(run-hook-with-args 'ido-before-fallback-functions
-			    (or fallback 'switch-to-buffer))
-	(call-interactively (or fallback 'switch-to-buffer)))
+			    (or ido-fallback 'switch-to-buffer))
+	(call-interactively (or ido-fallback 'switch-to-buffer)))
     (let* ((ido-context-switch-command switch-cmd)
 	   (ido-current-directory nil)
 	   (ido-directory-nonreadable nil)
@@ -2245,7 +2248,7 @@ If cursor is not at the end of the user input, move to end of input."
 
        ((eq ido-exit 'fallback)
 	(let ((read-buffer-function nil))
-	  (setq this-command (or fallback 'switch-to-buffer))
+	  (setq this-command (or ido-fallback 'switch-to-buffer))
 	  (run-hook-with-args 'ido-before-fallback-functions this-command)
 	  (call-interactively this-command)))
 
@@ -2337,7 +2340,7 @@ If cursor is not at the end of the user input, move to end of input."
   ;; Add final slash to result in case it was missing from DEFAULT-DIRECTORY.
   (ido-final-slash (expand-file-name (or dir default-directory)) t))
 
-(defun ido-file-internal (method &optional fallback default prompt item initial switch-cmd)
+(defun ido-file-internal (method &optional ido-fallback default prompt item initial switch-cmd)
   ;; Internal function for ido-find-file and friends
   (unless item
     (setq item 'file))
@@ -2412,7 +2415,7 @@ If cursor is not at the end of the user input, move to end of input."
 	;; we don't want to change directory of current buffer.
 	(let ((default-directory ido-current-directory)
 	      (read-file-name-function nil))
-	  (setq this-command (or fallback 'find-file))
+	  (setq this-command (or ido-fallback 'find-file))
 	  (run-hook-with-args 'ido-before-fallback-functions this-command)
 	  (call-interactively this-command)))
 
@@ -2496,10 +2499,10 @@ If cursor is not at the end of the user input, move to end of input."
        ((eq method 'read-only)
 	(ido-record-work-file filename)
 	(setq filename (concat ido-current-directory filename))
-	(ido-record-command fallback filename)
+	(ido-record-command ido-fallback filename)
 	(ido-record-work-directory)
-	(run-hook-with-args 'ido-before-fallback-functions fallback)
-	(funcall fallback filename))
+	(run-hook-with-args 'ido-before-fallback-functions ido-fallback)
+	(funcall ido-fallback filename))
 
        ((eq method 'insert)
 	(ido-record-work-file filename)
-- 
2.14.1