Subject: bug#35564: [PATCH v4] Tweak dired warning about "wildcard" characters

From: Kévin Le Gouguec <[email-masked]>
Date: Wed, 03 Jul 2019 21:47:40 +0200

This series of patches consists in

- the same 2 patches as v3
- Noam's refactoring
- some amendments ("occurrence", order of arguments in tests)
- a proof-of-concept for marking the occurrences with '^'

Here is a list of improvements that I plan on tackling Soonish™

1. refrain from adding markers if the minibuffer is not wide enough,

2. use (:inherit '(warning underline)) instead of warning, so that
    - if the warning face has some underlining, it is used,
    - otherwise the underline face makes sure that we don't rely only on
      colors.

Thank you all for your your reviews and your patience.  Sorry I can't
manage to take more time to work on this.

>From 1f1e6c974a56e834ee09446bac3ab41e6cd6f9af Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?K=C3=A9vin=20Le=20Gouguec?= <[email-masked]>
Date: Fri, 7 Jun 2019 17:03:59 +0200
Subject: [PATCH 1/5] Preserve text properties in y-or-n-p prompts

* lisp/subr.el (read--propertize-prompt): New function to append
the prompt face to a string.
(y-or-n-p): Use it instead of discarding potential text
properties.

(Bug#35564)
---
 lisp/subr.el | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/lisp/subr.el b/lisp/subr.el
index 4a1649f601..c59f13b24c 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -2338,6 +2338,9 @@ memory-limit
 
 ;;;; Input and display facilities.
 
+(defun read--propertize-prompt (prompt)
+  (add-face-text-property 0 (length prompt) 'minibuffer-prompt t prompt))
+
 (defconst read-key-empty-map (make-sparse-keymap))
 
 (defvar read-key-delay 0.01) ;Fast enough for 100Hz repeat rate, hopefully.
@@ -2675,14 +2678,14 @@ y-or-n-p
           (let* ((scroll-actions '(recenter scroll-up scroll-down
 				   scroll-other-window scroll-other-window-down))
 		 (key
-                  (let ((cursor-in-echo-area t))
+                  (let ((cursor-in-echo-area t)
+                        (prompt (if (memq answer scroll-actions)
+                                    prompt
+                                  (concat "Please answer y or n.  " prompt))))
                     (when minibuffer-auto-raise
                       (raise-frame (window-frame (minibuffer-window))))
-                    (read-key (propertize (if (memq answer scroll-actions)
-                                              prompt
-                                            (concat "Please answer y or n.  "
-                                                    prompt))
-                                          'face 'minibuffer-prompt)))))
+                    (read--propertize-prompt prompt)
+                    (read-key prompt))))
             (setq answer (lookup-key query-replace-map (vector key) t))
             (cond
 	     ((memq answer '(skip act)) nil)
-- 
2.22.0

>From 2fbda185484b45a9fa70518c064ad55b884387c5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?K=C3=A9vin=20Le=20Gouguec?= <[email-masked]>
Date: Fri, 7 Jun 2019 17:19:44 +0200
Subject: [PATCH 2/5] Tweak dired warning about "wildcard" characters

Non-isolated '?' and '*' characters may be quoted, or
backslash-escaped; we do not know for a fact that the shell will
interpret them as wildcards.

Rephrase the prompt and highlight the characters so that the user sees
exactly what we are talking about.

* lisp/dired-aux.el (dired--isolated-char-p)
(dired--highlight-nosubst-char, dired--no-subst-prompt): New
functions.
(dired-do-shell-command): Use them.

* test/lisp/dired-aux-tests.el (dired-test-isolated-char-p)
(dired-test-highlight-metachar): Test the new functions.

(Bug#35564)
---
 lisp/dired-aux.el            | 42 ++++++++++++++++++++++++++++++++----
 test/lisp/dired-aux-tests.el | 28 ++++++++++++++++++++++++
 2 files changed, 66 insertions(+), 4 deletions(-)

diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el
index 5e4ec4d1ec..079e4f102f 100644
--- a/lisp/dired-aux.el
+++ b/lisp/dired-aux.el
@@ -79,6 +79,42 @@ dired--star-or-qmark-p
                (funcall (if keep #'string-match-p #'string-match) x string))
              regexps)))
 
+(defun dired--isolated-char-p (command pos)
+  "Assert whether the character at POS is isolated within COMMAND.
+A character is isolated if:
+- it is surrounded by whitespace, the start of the command, or
+  the end of the command,
+- it is surrounded by `\\=`' characters."
+  (let ((start (max 0 (1- pos)))
+        (char (string (aref command pos))))
+    (and (string-match
+          (rx (or (seq (or bos blank)
+                       (group-n 1 (literal char))
+                       (or eos blank))
+                  (seq ?` (group-n 1 (literal char)) ?`)))
+          command start)
+         (= pos (match-beginning 1)))))
+
+(defun dired--highlight-nosubst-char (command char)
+  "Highlight occurences of CHAR that are not isolated in COMMAND.
+These occurences will not be substituted; they will be sent as-is
+to the shell, which may interpret them as wildcards."
+  (save-match-data
+    (let ((highlighted (substring-no-properties command))
+          (pos 0))
+      (while (string-match (regexp-quote char) command pos)
+        (let ((start (match-beginning 0))
+              (end (match-end 0)))
+          (unless (dired--isolated-char-p command start)
+            (add-face-text-property start end 'warning nil highlighted))
+          (setq pos end)))
+      highlighted)))
+
+(defun dired--no-subst-prompt (command char)
+  (let ((highlighted-command (dired--highlight-nosubst-char command char))
+        (prompt "Confirm--the highlighted characters will not be substituted:"))
+    (format-message "%s\n%s\nProceed?" prompt highlighted-command)))
+
 ;;;###autoload
 (defun dired-diff (file &optional switches)
   "Compare file at point with FILE using `diff'.
@@ -759,11 +795,9 @@ dired-do-shell-command
          (ok (cond ((not (or on-each no-subst))
 	            (error "You can not combine `*' and `?' substitution marks"))
 	           ((need-confirm-p command "*")
-	            (y-or-n-p (format-message
-			       "Confirm--do you mean to use `*' as a wildcard? ")))
+	            (y-or-n-p (dired--no-subst-prompt command "*")))
 	           ((need-confirm-p command "?")
-	            (y-or-n-p (format-message
-			       "Confirm--do you mean to use `?' as a wildcard? ")))
+	            (y-or-n-p (dired--no-subst-prompt command "?")))
 	           (t))))
     (cond ((not ok) (message "Command canceled"))
           (t
diff --git a/test/lisp/dired-aux-tests.el b/test/lisp/dired-aux-tests.el
index ccd3192792..80b6393931 100644
--- a/test/lisp/dired-aux-tests.el
+++ b/test/lisp/dired-aux-tests.el
@@ -114,6 +114,34 @@ dired-test-bug30624
         (mapc #'delete-file `(,file1 ,file2))
         (kill-buffer buf)))))
 
+(ert-deftest dired-test-isolated-char-p ()
+  (should (dired--isolated-char-p "?" 0))
+  (should (dired--isolated-char-p "? " 0))
+  (should (dired--isolated-char-p " ?" 1))
+  (should (dired--isolated-char-p " ? " 1))
+  (should (dired--isolated-char-p "foo bar ? baz" 8))
+  (should (dired--isolated-char-p "foo -i`?`" 7))
+  (should-not (dired--isolated-char-p "foo `bar`?" 9))
+  (should-not (dired--isolated-char-p "foo 'bar?'" 8))
+  (should-not (dired--isolated-char-p "foo bar?baz" 7))
+  (should-not (dired--isolated-char-p "foo bar?" 7)))
+
+(ert-deftest dired-test-highlight-metachar ()
+  "Check that non-isolated meta-characters are highlighted"
+  (let* ((command "sed -r -e 's/oo?/a/' -e 's/oo?/a/' ? `?`")
+         (result (dired--highlight-nosubst-char command "?")))
+    (should-not (text-property-not-all 1 14 'face nil result))
+    (should (equal 'warning (get-text-property 15 'face result)))
+    (should-not (text-property-not-all 16 28 'face nil result))
+    (should (equal 'warning (get-text-property 29 'face result)))
+    (should-not (text-property-not-all 30 39 'face nil result)))
+  (let* ((command "sed -e 's/o*/a/' -e 's/o*/a/'")
+         (result (dired--highlight-nosubst-char command "*")))
+    (should-not (text-property-not-all 1 10 'face nil result))
+    (should (equal 'warning (get-text-property 11 'face result)))
+    (should-not (text-property-not-all 12 23 'face nil result))
+    (should (equal 'warning (get-text-property 24 'face result)))
+    (should-not (text-property-not-all 25 29 'face nil result))))
 
 (provide 'dired-aux-tests)
 ;; dired-aux-tests.el ends here
-- 
2.22.0

>From 0ecd865a837665b6d7549f1a18eff3b46988a7dd Mon Sep 17 00:00:00 2001
From: Noam Postavsky <[email-masked]>
Date: Thu, 27 Jun 2019 19:15:56 -0400
Subject: [PATCH 3/5] Dedup dired-aux isolated char searching (Bug#35564)

* lisp/dired-aux.el (dired-isolated-string-re): Use explicitly
numbered groups.
(dired--star-or-qmark-p): Add START parameter.  Make sure to return
the first isolated match.
(dired--no-subst-prompt): Operate on a list of positions rather than
searching again for isolated chars.  Shorten prompt, and include the
character being asked about in the question (to make it clearer, and
in case the user can't see the fontification for whatever reason,
e.g., screen reader).
(dired--isolated-char-p): Remove.
(dired--need-confirm-positions): New function.
(dired-do-shell-command): Use it.
* test/lisp/dired-aux-tests.el (dired-test-isolated-char-p): Remove.
(dired-test-highlight-metachar): Adjust to new functions.  Make sure
that `*` isn't considered isolated.
---
 lisp/dired-aux.el            | 113 ++++++++++++++++-------------------
 test/lisp/dired-aux-tests.el |  31 +++++-----
 2 files changed, 67 insertions(+), 77 deletions(-)

diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el
index 079e4f102f..47e1d38223 100644
--- a/lisp/dired-aux.el
+++ b/lisp/dired-aux.el
@@ -60,60 +60,60 @@ dired-isolated-string-re
 of a string followed/prefixed with an space.
 The regexp capture the preceding blank, STRING and the following blank as
 the groups 1, 2 and 3 respectively."
-  (format "\\(\\`\\|[ \t]\\)\\(%s\\)\\([ \t]\\|\\'\\)" string))
+  (format "\\(?1:\\`\\|[ \t]\\)\\(?2:%s\\)\\(?3:[ \t]\\|\\'\\)" string))
 
-(defun dired--star-or-qmark-p (string match &optional keep)
+(defun dired--star-or-qmark-p (string match &optional keep start)
   "Return non-nil if STRING contains isolated MATCH or `\\=`?\\=`'.
 MATCH should be the strings \"?\", `\\=`?\\=`', \"*\" or nil.  The latter
 means STRING contains either \"?\" or `\\=`?\\=`' or \"*\".
 If optional arg KEEP is non-nil, then preserve the match data.  Otherwise,
 this function changes it and saves MATCH as the second match group.
+START is the position to start matching from.
 
 Isolated means that MATCH is surrounded by spaces or at the beginning/end
 of STRING followed/prefixed with an space.  A match to `\\=`?\\=`',
 isolated or not, is also valid."
-  (let ((regexps (list (dired-isolated-string-re (if match (regexp-quote match) "[*?]")))))
+  (let ((regexp (dired-isolated-string-re (if match (regexp-quote match) "[*?]"))))
     (when (or (null match) (equal match "?"))
-      (setq regexps (append (list "\\(\\)\\(`\\?`\\)\\(\\)") regexps)))
-    (cl-some (lambda (x)
-               (funcall (if keep #'string-match-p #'string-match) x string))
-             regexps)))
-
-(defun dired--isolated-char-p (command pos)
-  "Assert whether the character at POS is isolated within COMMAND.
-A character is isolated if:
-- it is surrounded by whitespace, the start of the command, or
-  the end of the command,
-- it is surrounded by `\\=`' characters."
-  (let ((start (max 0 (1- pos)))
-        (char (string (aref command pos))))
-    (and (string-match
-          (rx (or (seq (or bos blank)
-                       (group-n 1 (literal char))
-                       (or eos blank))
-                  (seq ?` (group-n 1 (literal char)) ?`)))
-          command start)
-         (= pos (match-beginning 1)))))
-
-(defun dired--highlight-nosubst-char (command char)
-  "Highlight occurences of CHAR that are not isolated in COMMAND.
-These occurences will not be substituted; they will be sent as-is
-to the shell, which may interpret them as wildcards."
-  (save-match-data
-    (let ((highlighted (substring-no-properties command))
-          (pos 0))
-      (while (string-match (regexp-quote char) command pos)
-        (let ((start (match-beginning 0))
-              (end (match-end 0)))
-          (unless (dired--isolated-char-p command start)
-            (add-face-text-property start end 'warning nil highlighted))
-          (setq pos end)))
-      highlighted)))
-
-(defun dired--no-subst-prompt (command char)
-  (let ((highlighted-command (dired--highlight-nosubst-char command char))
-        (prompt "Confirm--the highlighted characters will not be substituted:"))
-    (format-message "%s\n%s\nProceed?" prompt highlighted-command)))
+      (cl-callf concat regexp "\\|\\(?1:\\)\\(?2:`\\?`\\)\\(?3:\\)"))
+    (funcall (if keep #'string-match-p #'string-match) regexp string start)))
+
+(defun dired--need-confirm-positions (command string)
+  "Search for non-isolated matches of STRING in COMMAND.
+Return a list of positions that match STRING, but would not be
+considered \"isolated\" by `dired--star-or-qmark-p'."
+  (cl-assert (= (length string) 1))
+  (let ((start 0)
+        (isolated-char-positions nil)
+        (confirm-positions nil)
+        (regexp (regexp-quote string)))
+    ;; Collect all ? and * surrounded by spaces and `?`.
+    (while (dired--star-or-qmark-p command string nil start)
+      (push (cons (match-beginning 2) (match-end 2))
+            isolated-char-positions)
+      (setq start (match-end 2)))
+    ;; Now collect any remaining ? and *.
+    (setq start 0)
+    (while (string-match regexp command start)
+      (unless (cl-member (match-beginning 0) isolated-char-positions
+                         :test (lambda (pos match)
+                                 (<= (car match) pos (cdr match))))
+        (push (match-beginning 0) confirm-positions))
+      (setq start (match-end 0)))
+    confirm-positions))
+
+(defun dired--no-subst-prompt (char-positions command)
+  (cl-callf substring-no-properties command)
+  (dolist (pos char-positions)
+    (add-face-text-property pos (1+ pos) 'warning nil command))
+  (concat command "\n"
+          (format-message
+           (ngettext "Send %d occurence of `%s' as-is to shell?"
+                     "Send %d occurences of `%s' as-is to shell?"
+                     (length char-positions))
+           (length char-positions)
+           (propertize (string (aref command (car char-positions)))
+                       'face 'warning))))
 
 ;;;###autoload
 (defun dired-diff (file &optional switches)
@@ -779,26 +779,19 @@ dired-do-shell-command
       (dired-read-shell-command "! on %s: " current-prefix-arg files)
       current-prefix-arg
       files)))
-  (cl-flet ((need-confirm-p
-             (cmd str)
-             (let ((res cmd)
-                   (regexp (regexp-quote str)))
-               ;; Drop all ? and * surrounded by spaces and `?`.
-               (while (and (string-match regexp res)
-                           (dired--star-or-qmark-p res str))
-                 (setq res (replace-match "" t t res 2)))
-               (string-match regexp res))))
   (let* ((on-each (not (dired--star-or-qmark-p command "*" 'keep)))
 	 (no-subst (not (dired--star-or-qmark-p command "?" 'keep)))
+         (confirmations nil)
          ;; Get confirmation for wildcards that may have been meant
          ;; to control substitution of a file name or the file name list.
-         (ok (cond ((not (or on-each no-subst))
-	            (error "You can not combine `*' and `?' substitution marks"))
-	           ((need-confirm-p command "*")
-	            (y-or-n-p (dired--no-subst-prompt command "*")))
-	           ((need-confirm-p command "?")
-	            (y-or-n-p (dired--no-subst-prompt command "?")))
-	           (t))))
+         (ok (cond
+              ((not (or on-each no-subst))
+               (error "You can not combine `*' and `?' substitution marks"))
+              ((setq confirmations (dired--need-confirm-positions command "*"))
+               (y-or-n-p (dired--no-subst-prompt confirmations command)))
+              ((setq confirmations (dired--need-confirm-positions command "?"))
+               (y-or-n-p (dired--no-subst-prompt confirmations command)))
+              (t))))
     (cond ((not ok) (message "Command canceled"))
           (t
            (if on-each
@@ -809,7 +802,7 @@ dired-do-shell-command
 	                          nil file-list)
 	     ;; execute the shell command
 	     (dired-run-shell-command
-	      (dired-shell-stuff-it command file-list nil arg))))))))
+              (dired-shell-stuff-it command file-list nil arg)))))))
 
 ;; Might use {,} for bash or csh:
 (defvar dired-mark-prefix ""
diff --git a/test/lisp/dired-aux-tests.el b/test/lisp/dired-aux-tests.el
index 80b6393931..3f4bfffaf6 100644
--- a/test/lisp/dired-aux-tests.el
+++ b/test/lisp/dired-aux-tests.el
@@ -114,34 +114,31 @@ dired-test-bug30624
         (mapc #'delete-file `(,file1 ,file2))
         (kill-buffer buf)))))
 
-(ert-deftest dired-test-isolated-char-p ()
-  (should (dired--isolated-char-p "?" 0))
-  (should (dired--isolated-char-p "? " 0))
-  (should (dired--isolated-char-p " ?" 1))
-  (should (dired--isolated-char-p " ? " 1))
-  (should (dired--isolated-char-p "foo bar ? baz" 8))
-  (should (dired--isolated-char-p "foo -i`?`" 7))
-  (should-not (dired--isolated-char-p "foo `bar`?" 9))
-  (should-not (dired--isolated-char-p "foo 'bar?'" 8))
-  (should-not (dired--isolated-char-p "foo bar?baz" 7))
-  (should-not (dired--isolated-char-p "foo bar?" 7)))
-
 (ert-deftest dired-test-highlight-metachar ()
   "Check that non-isolated meta-characters are highlighted"
   (let* ((command "sed -r -e 's/oo?/a/' -e 's/oo?/a/' ? `?`")
-         (result (dired--highlight-nosubst-char command "?")))
+         (prompt (dired--no-subst-prompt
+                  command
+                  (dired--need-confirm-positions command "?")))
+         (result (and (string-match (regexp-quote command) prompt)
+                      (match-string 0 prompt))))
     (should-not (text-property-not-all 1 14 'face nil result))
     (should (equal 'warning (get-text-property 15 'face result)))
     (should-not (text-property-not-all 16 28 'face nil result))
     (should (equal 'warning (get-text-property 29 'face result)))
     (should-not (text-property-not-all 30 39 'face nil result)))
-  (let* ((command "sed -e 's/o*/a/' -e 's/o*/a/'")
-         (result (dired--highlight-nosubst-char command "*")))
+  ;; Note that `?` is considered isolated, but `*` is not.
+  (let* ((command "sed -e 's/o*/a/' -e 's/o`*` /a/'")
+         (prompt (dired--no-subst-prompt
+                  command
+                  (dired--need-confirm-positions command "*")))
+         (result (and (string-match (regexp-quote command) prompt)
+                      (match-string 0 prompt))))
     (should-not (text-property-not-all 1 10 'face nil result))
     (should (equal 'warning (get-text-property 11 'face result)))
     (should-not (text-property-not-all 12 23 'face nil result))
-    (should (equal 'warning (get-text-property 24 'face result)))
-    (should-not (text-property-not-all 25 29 'face nil result))))
+    (should (equal 'warning (get-text-property 25 'face result)))
+    (should-not (text-property-not-all 26 32 'face nil result))))
 
 (provide 'dired-aux-tests)
 ;; dired-aux-tests.el ends here
-- 
2.22.0

>From 8944a2c77e04012593450edd391a0e4ac0be090d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?K=C3=A9vin=20Le=20Gouguec?= <[email-masked]>
Date: Wed, 3 Jul 2019 21:29:38 +0200
Subject: [PATCH 4/5] fixup! Dedup dired-aux isolated char searching
 (Bug#35564)

---
 lisp/dired-aux.el            | 4 ++--
 test/lisp/dired-aux-tests.el | 8 ++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el
index 47e1d38223..7ea1191c49 100644
--- a/lisp/dired-aux.el
+++ b/lisp/dired-aux.el
@@ -108,8 +108,8 @@ dired--no-subst-prompt
     (add-face-text-property pos (1+ pos) 'warning nil command))
   (concat command "\n"
           (format-message
-           (ngettext "Send %d occurence of `%s' as-is to shell?"
-                     "Send %d occurences of `%s' as-is to shell?"
+           (ngettext "Send %d occurrence of `%s' as-is to shell?"
+                     "Send %d occurrences of `%s' as-is to shell?"
                      (length char-positions))
            (length char-positions)
            (propertize (string (aref command (car char-positions)))
diff --git a/test/lisp/dired-aux-tests.el b/test/lisp/dired-aux-tests.el
index 3f4bfffaf6..ff18edddb6 100644
--- a/test/lisp/dired-aux-tests.el
+++ b/test/lisp/dired-aux-tests.el
@@ -118,8 +118,8 @@ dired-test-highlight-metachar
   "Check that non-isolated meta-characters are highlighted"
   (let* ((command "sed -r -e 's/oo?/a/' -e 's/oo?/a/' ? `?`")
          (prompt (dired--no-subst-prompt
-                  command
-                  (dired--need-confirm-positions command "?")))
+                  (dired--need-confirm-positions command "?")
+                  command))
          (result (and (string-match (regexp-quote command) prompt)
                       (match-string 0 prompt))))
     (should-not (text-property-not-all 1 14 'face nil result))
@@ -130,8 +130,8 @@ dired-test-highlight-metachar
   ;; Note that `?` is considered isolated, but `*` is not.
   (let* ((command "sed -e 's/o*/a/' -e 's/o`*` /a/'")
          (prompt (dired--no-subst-prompt
-                  command
-                  (dired--need-confirm-positions command "*")))
+                  (dired--need-confirm-positions command "*")
+                  command))
          (result (and (string-match (regexp-quote command) prompt)
                       (match-string 0 prompt))))
     (should-not (text-property-not-all 1 10 'face nil result))
-- 
2.22.0

>From 7f28faa497419aeda4fed6ec413b7d6060f2c203 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?K=C3=A9vin=20Le=20Gouguec?= <[email-masked]>
Date: Wed, 3 Jul 2019 21:17:57 +0200
Subject: [PATCH 5/5] Add '^' markers below non-isolated chars in dired prompt

* lisp/dired-aux.el (dired--mark-positions): New function.
(dired--no-subst-prompt): Use it.

* test/lisp/dired-aux-tests.el (dired-test-highlight-metachar):
Add assertion for '^' marker positions.

(Bug#35564)
---
 lisp/dired-aux.el            | 25 +++++++++++++++++--------
 test/lisp/dired-aux-tests.el |  8 ++++++--
 2 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el
index 7ea1191c49..cc11f2674f 100644
--- a/lisp/dired-aux.el
+++ b/lisp/dired-aux.el
@@ -102,18 +102,27 @@ dired--need-confirm-positions
       (setq start (match-end 0)))
     confirm-positions))
 
+(defun dired--mark-positions (positions)
+  (let* ((positions (sort positions '<))
+         (markers (make-string (1+ (car (last positions))) ?\s)))
+    (dolist (pos positions)
+      (setf (aref markers pos) ?^))
+    markers))
+
 (defun dired--no-subst-prompt (char-positions command)
   (cl-callf substring-no-properties command)
   (dolist (pos char-positions)
     (add-face-text-property pos (1+ pos) 'warning nil command))
-  (concat command "\n"
-          (format-message
-           (ngettext "Send %d occurrence of `%s' as-is to shell?"
-                     "Send %d occurrences of `%s' as-is to shell?"
-                     (length char-positions))
-           (length char-positions)
-           (propertize (string (aref command (car char-positions)))
-                       'face 'warning))))
+  (let ((markers (dired--mark-positions char-positions)))
+    (concat command "\n"
+            markers "\n"
+            (format-message
+             (ngettext "Send %d occurrence of `%s' as-is to shell?"
+                       "Send %d occurrences of `%s' as-is to shell?"
+                       (length char-positions))
+             (length char-positions)
+             (propertize (string (aref command (car char-positions)))
+                         'face 'warning)))))
 
 ;;;###autoload
 (defun dired-diff (file &optional switches)
diff --git a/test/lisp/dired-aux-tests.el b/test/lisp/dired-aux-tests.el
index ff18edddb6..fbadfcbf12 100644
--- a/test/lisp/dired-aux-tests.el
+++ b/test/lisp/dired-aux-tests.el
@@ -117,6 +117,7 @@ dired-test-bug30624
 (ert-deftest dired-test-highlight-metachar ()
   "Check that non-isolated meta-characters are highlighted"
   (let* ((command "sed -r -e 's/oo?/a/' -e 's/oo?/a/' ? `?`")
+         (markers "               ^             ^")
          (prompt (dired--no-subst-prompt
                   (dired--need-confirm-positions command "?")
                   command))
@@ -126,9 +127,11 @@ dired-test-highlight-metachar
     (should (equal 'warning (get-text-property 15 'face result)))
     (should-not (text-property-not-all 16 28 'face nil result))
     (should (equal 'warning (get-text-property 29 'face result)))
-    (should-not (text-property-not-all 30 39 'face nil result)))
+    (should-not (text-property-not-all 30 39 'face nil result))
+    (should (string-match (regexp-quote markers) prompt (1+ (length command)))))
   ;; Note that `?` is considered isolated, but `*` is not.
   (let* ((command "sed -e 's/o*/a/' -e 's/o`*` /a/'")
+         (markers "           ^             ^")
          (prompt (dired--no-subst-prompt
                   (dired--need-confirm-positions command "*")
                   command))
@@ -138,7 +141,8 @@ dired-test-highlight-metachar
     (should (equal 'warning (get-text-property 11 'face result)))
     (should-not (text-property-not-all 12 23 'face nil result))
     (should (equal 'warning (get-text-property 25 'face result)))
-    (should-not (text-property-not-all 26 32 'face nil result))))
+    (should-not (text-property-not-all 26 32 'face nil result))
+    (should (string-match (regexp-quote markers) prompt (1+ (length command))))))
 
 (provide 'dired-aux-tests)
 ;; dired-aux-tests.el ends here
-- 
2.22.0