tramp simplified syntax and ido interaction

[Robert Pluim]

Hi,

I'm using emacs master. I wanted to try out tramp's simplified syntax,
but this has a bad interaction with ido which I also use. I tracked it
down to ido-make-file-list, which does not handle empty strings in its
potential completion list. It's not clear to me if this is an ido or a
tramp bug, but one potential fix is attached.

Reproduction from emacs -Q :

; Eval this form
(custom-set-variables
 '(ido-everywhere t)
 '(ido-max-dir-file-cache 10)
 '(ido-mode (quote both) nil (ido))
 '(ido-use-filename-at-point (quote guess))
)
; find a file using normal tramp syntax, then eval the next two lines
(tramp-change-syntax 'simplified)
(setq debug-on-error t)
; C-x C-f /f

Debugger entered--Lisp error: (args-out-of-range "" 0 1)
  substring("" 0 1)
  (string-equal (substring x 0 1) ".")
  (if (string-equal (substring x 0 1) ".") x)
  (closure ((default . "etc/") ido-completing-read ido-context-switch-command 
ido-find-literal ido-saved-vc-hb ido-pre-merge-state ido-try-merged-list 
ido-use-merged-list ido-work-file-index ido-work-directory-index 
ido-rotate-temp ido-temp-list ido-show-confirm-message ido-require-match 
ido-entry-buffer ido-enable-virtual-buffers ido-process-ignore-lists-inhibit 
ido-process-ignore-lists ido-keep-item-list ido-directory-too-big 
ido-directory-nonreadable ido-ignored-list ido-choice-list ido-cur-list 
ido-default-item ido-cur-item recentf-list t) (x) (if (string-equal (substring 
x 0 1) ".") x))("")
  mapcar((closure ((default . "etc/") ido-completing-read 
ido-context-switch-command ido-find-literal ido-saved-vc-hb ido-pre-merge-state 
ido-try-merged-list ido-use-merged-list ido-work-file-index 
ido-work-directory-index ido-rotate-temp ido-temp-list ido-show-confirm-message 
ido-require-match ido-entry-buffer ido-enable-virtual-buffers 
ido-process-ignore-lists-inhibit ido-process-ignore-lists ido-keep-item-list 
ido-directory-too-big ido-directory-nonreadable ido-ignored-list 
ido-choice-list ido-cur-list ido-default-item ido-cur-item recentf-list t) (x) 
(if (string-equal (substring x 0 1) ".") x)) ("" "" "bin/" "boot/" "cdrom/" 
"dev/" "etc/" "home/" "initrd.img" "initrd.img.old" "lib/" "lib32/" "lib64/" 
"lost+found/" "media/" "mnt/" "opt/" "proc/" "root/" "run/" "sbin/" "snap/" 
"srv/" "sys/" "tmp/" "usr/" "var/" "vmlinuz" "vmlinuz.old" "fmail-3000:" 
"fortimail-vm:" "fsiem:" "fsm-robert:" "kubuntu-vm:" "rpluim-ubuntu:" 
"secops3700f:"))
  (delq nil (mapcar (function (lambda (x) (if (string-equal (substring x 0 1) 
".") x))) ido-temp-list))
  (ido-to-end (delq nil (mapcar (function (lambda (x) (if (string-equal 
(substring x 0 1) ".") x))) ido-temp-list)))
  (let ((ido-temp-list (ido-make-file-list-1 ido-current-directory))) (setq 
ido-temp-list (sort ido-temp-list (if ido-file-extensions-order (function 
ido-file-extension-lessp) (function ido-file-lessp)))) (if (ido-is-tramp-root 
ido-current-directory) nil (let ((default-directory ido-current-directory)) 
(ido-to-end (delq nil (mapcar (function (lambda (x) (if (or (and (string-match 
".:\\'" x) (not (ido-local-file-exists-p x))) (and (not (ido-final-slash x)) 
(let (file-name-handler-alist) (get-file-buffer x)))) x))) ido-temp-list))))) 
(ido-to-end (delq nil (mapcar (function (lambda (x) (if (string-equal 
(substring x 0 1) ".") x))) ido-temp-list))) (if (and default (member default 
ido-temp-list)) (if (or ido-rotate-temp ido-rotate-file-list-default) (if 
(equal default (car ido-temp-list)) nil (let ((l ido-temp-list) k) (while (and 
l (cdr l) (not (equal default (car (cdr l))))) (setq l (cdr l))) (setq k (cdr 
l)) (setcdr l nil) (nconc k ido-temp-list) (setq ido-temp-list k))) (setq 
ido-temp-list (delete default ido-temp-list)) (setq ido-temp-list (cons default 
ido-temp-list)))) (if ido-show-dot-for-dired (progn (setq ido-temp-list (delete 
"." ido-temp-list)) (setq ido-temp-list (cons "." ido-temp-list)))) (run-hooks 
'ido-make-file-list-hook) ido-temp-list)
  ido-make-file-list("etc/")

Regards

Robert

>From f8c25dd71b5e3e05f15b4ba2dc0fb6328f99513a Mon Sep 17 00:00:00 2001
From: Robert Pluim <address@hidden>
Date: Wed, 2 Aug 2017 11:17:01 +0200
Subject: [PATCH] Use string-match to check for dotfiles in ido

        * lisp/ido.el (ido-make-file-list): Use string-match to check
        for dotfiles instead of substring, as when using tramp
        simplified syntax ido-temp-list may contain empty strings
---
 lisp/ido.el | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lisp/ido.el b/lisp/ido.el
index 7253a8c840..c4eb1bc11e 100644
--- a/lisp/ido.el
+++ b/lisp/ido.el
@@ -3679,7 +3679,7 @@ ido-make-file-list
                    ido-temp-list)))))
     (ido-to-end  ;; move . files to end
      (delq nil (mapcar
-               (lambda (x) (if (string-equal (substring x 0 1) ".") x))
+               (lambda (x) (if (string-match "^\." x) x))
                ido-temp-list)))
     (if (and default (member default ido-temp-list))
        (if (or ido-rotate-temp ido-rotate-file-list-default)
-- 
2.14.0.rc1