Make Tramp aware of completion-regexp-list (don't merge)

* lisp/net/tramp.el (tramp-skeleton-file-name-all-completions):
New defmacro.
(tramp-completion-handle-file-name-all-completions):
* lisp/net/tramp-adb.el (tramp-adb-handle-file-name-all-completions):
* lisp/net/tramp-crypt.el (tramp-crypt-handle-file-name-all-completions):
* lisp/net/tramp-fuse.el (tramp-fuse-handle-file-name-all-completions):
* lisp/net/tramp-gvfs.el (tramp-gvfs-handle-file-name-all-completions):
* lisp/net/tramp-sh.el (tramp-sh-handle-file-name-all-completions):
* lisp/net/tramp-smb.el (tramp-smb-handle-file-name-all-completions):
* lisp/net/tramp-sudoedit.el
(tramp-sudoedit-handle-file-name-all-completions): Use it.

lisp/net/tramp-adb.el

@@ -449,7 +449,7 @@ Emacs dired can't find files."
 
 (defun tramp-adb-handle-file-name-all-completions (filename directory)
   "Like `file-name-all-completions' for Tramp files."
-  (tramp-compat-ignore-error file-missing
+  (tramp-skeleton-file-name-all-completions filename directory
     (all-completions
      filename
      (with-parsed-tramp-file-name (expand-file-name directory) nil
@@ -464,17 +464,14 @@ Emacs dired can't find files."
 		(file-name-as-directory f)
 	      f))
 	  (with-current-buffer (tramp-get-buffer v)
-	    (delete-dups
 	    (append
 	     ;; On some file systems like "sdcard", "." and ".." are
-	      ;; not included.  We fix this by `delete-dups'.
+	     ;; not included.
 	     '("." "..")
-	      (delq
-	       nil
 	     (mapcar
 	      (lambda (l)
 		(and (not (string-match-p (rx bol (* blank) eol) l)) l))
-		(split-string (buffer-string) "\n"))))))))))))
+	      (split-string (buffer-string) "\n" 'omit))))))))))
 
 (defun tramp-adb-handle-file-local-copy (filename)
   "Like `file-local-copy' for Tramp files."

lisp/net/tramp-crypt.el

@@ -735,7 +735,7 @@ absolute file names."
 
 (defun tramp-crypt-handle-file-name-all-completions (filename directory)
   "Like `file-name-all-completions' for Tramp files."
-  (tramp-compat-ignore-error file-missing
+  (tramp-skeleton-file-name-all-completions filename directory
     (all-completions
      filename
      (let* (completion-regexp-list

lisp/net/tramp-fuse.el

@@ -104,11 +104,10 @@
 
 (defun tramp-fuse-handle-file-name-all-completions (filename directory)
   "Like `file-name-all-completions' for Tramp files."
+  (tramp-skeleton-file-name-all-completions filename directory
     (tramp-fuse-remove-hidden-files
-   (tramp-compat-ignore-error file-missing
      (all-completions
       filename
-      (delete-dups
       (append
        (file-name-all-completions
 	filename (tramp-fuse-local-file-name directory))
@@ -119,7 +118,7 @@
 	     (catch 'match
 	       (dolist (elt completion-regexp-list)
 		 (unless (string-match-p elt item) (throw 'match nil)))
-		(setq result (cons (concat item "/") result))))))))))))
+	       (setq result (cons (concat item "/") result)))))))))))
 
 ;; This function isn't used.
 (defun tramp-fuse-handle-insert-directory

lisp/net/tramp-gvfs.el

@@ -1434,8 +1434,8 @@ If FILE-SYSTEM is non-nil, return file system attributes."
 
 (defun tramp-gvfs-handle-file-name-all-completions (filename directory)
   "Like `file-name-all-completions' for Tramp files."
+  (tramp-skeleton-file-name-all-completions filename directory
     (unless (tramp-compat-string-search "/" filename)
-    (tramp-compat-ignore-error file-missing
       (all-completions
        filename
        (with-parsed-tramp-file-name (expand-file-name directory) nil

lisp/net/tramp-sh.el

@@ -1831,11 +1831,11 @@ ID-FORMAT valid values are `string' and `integer'."
 ;; files.
 (defun tramp-sh-handle-file-name-all-completions (filename directory)
   "Like `file-name-all-completions' for Tramp files."
+  (tramp-skeleton-file-name-all-completions filename directory
     (with-parsed-tramp-file-name (expand-file-name directory) nil
       (when (and (not (tramp-compat-string-search "/" filename))
 		 (tramp-connectable-p v))
 	(unless (tramp-compat-string-search "/" filename)
-      (tramp-compat-ignore-error file-missing
 	  (all-completions
 	   filename
 	   (with-tramp-file-property v localname "file-name-all-completions"
@@ -1869,7 +1869,8 @@ ID-FORMAT valid values are `string' and `integer'."
 		 (with-current-buffer (tramp-get-buffer v)
 		   (goto-char (point-max))
 		   (while (zerop (forward-line -1))
-		   (push (buffer-substring (point) (line-end-position)) result)))
+		     (push
+		      (buffer-substring (point) (line-end-position)) result)))
 		 result)))))))))
 
 ;; cp, mv and ln

lisp/net/tramp-smb.el

@@ -987,20 +987,19 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 ;; files.
 (defun tramp-smb-handle-file-name-all-completions (filename directory)
   "Like `file-name-all-completions' for Tramp files."
-  (tramp-compat-ignore-error file-missing
+  (tramp-skeleton-file-name-all-completions filename directory
     (all-completions
      filename
      (when (file-directory-p directory)
        (with-parsed-tramp-file-name (expand-file-name directory) nil
 	 (with-tramp-file-property v localname "file-name-all-completions"
-	   (delete-dups
 	   (mapcar
 	    (lambda (x)
 	      (list
 	       (if (tramp-compat-string-search "d" (nth 1 x))
 		   (file-name-as-directory (nth 0 x))
 		 (nth 0 x))))
-	     (tramp-smb-get-file-entries directory)))))))))
+	    (tramp-smb-get-file-entries directory))))))))
 
 (defun tramp-smb-handle-file-system-info (filename)
   "Like `file-system-info' for Tramp files."

lisp/net/tramp-sudoedit.el

@@ -467,7 +467,7 @@ the result will be a local, non-Tramp, file name."
 
 (defun tramp-sudoedit-handle-file-name-all-completions (filename directory)
   "Like `file-name-all-completions' for Tramp files."
-  (tramp-compat-ignore-error file-missing
+  (tramp-skeleton-file-name-all-completions filename directory
     (all-completions
      filename
      (with-parsed-tramp-file-name (expand-file-name directory) nil
@@ -481,13 +481,11 @@ the result will be a local, non-Tramp, file name."
 	    (if (ignore-errors (file-directory-p (expand-file-name f directory)))
 		(file-name-as-directory f)
 	      f))
-	  (delq
-	   nil
 	  (mapcar
 	   (lambda (l) (and (not (string-match-p (rx bol (* blank) eol) l)) l))
 	   (split-string
 	    (tramp-get-buffer-string (tramp-get-connection-buffer v))
-	     "\n" 'omit)))))))))
+	    "\n" 'omit))))))))
 
 (defun tramp-sudoedit-handle-file-readable-p (filename)
   "Like `file-readable-p' for Tramp files."

lisp/net/tramp.el

@@ -3069,12 +3069,30 @@ not in completion mode."
 
       (tramp-run-real-handler #'file-exists-p (list filename))))
 
+(defmacro tramp-skeleton-file-name-all-completions
+    (_filename _directory &rest body)
+  "Skeleton for `tramp-*-handle-filename-all-completions'.
+BODY is the backend specific code."
+  (declare (indent 2) (debug t))
+  `(tramp-compat-ignore-error file-missing
+     (delete-dups (delq nil
+       (let* ((case-fold-search read-file-name-completion-ignore-case)
+	      (regexp (mapconcat #'identity completion-regexp-list "\\|"))
+	      (result ,@body))
+	 (if (consp completion-regexp-list)
+	     ;; Discriminate over `completion-regexp-list'.
+	     (mapcar
+	      (lambda (x) (and (stringp x) (string-match-p regexp x) x))
+	      result)
+	   result))))))
+
 ;; Method, host name and user name completion.
 ;; `tramp-completion-dissect-file-name' returns a list of
 ;; `tramp-file-name' structures.  For all of them we return possible
 ;; completions.
 (defun tramp-completion-handle-file-name-all-completions (filename directory)
   "Like `file-name-all-completions' for partial Tramp files."
+  (tramp-skeleton-file-name-all-completions filename directory
     (let ((fullname
 	   (tramp-drop-volume-letter (expand-file-name filename directory)))
 	  ;; When `tramp-syntax' is `simplified', we need a default method.
@@ -3108,9 +3126,7 @@ not in completion mode."
 	       all-user-hosts)
 
 	  (unless localname ;; Nothing to complete.
-
 	    (if (or user host)
-
 		;; Method dependent user / host combinations.
 		(progn
 		  (mapc
@@ -3132,7 +3148,7 @@ not in completion mode."
 	      (setq result
 		    (append result (tramp-get-completion-methods m)))))))
 
-    ;; Unify list, add hop, remove nil elements.
+      ;; Add hop.
       (dolist (elt result)
 	(when elt
 	  (string-match tramp-prefix-regexp elt)
@@ -3142,7 +3158,6 @@ not in completion mode."
 	   result1)))
 
       ;; Complete local parts.
-    (delete-dups
       (append
        result1
        (ignore-errors