1 files changed, 13 insertions, 57 deletions

diff --git a/lisp/emacs-lisp/backtrace.el b/lisp/emacs-lisp/backtrace.el
index b9b08aa1b49..e47e2662afa 100644
--- a/lisp/emacs-lisp/backtrace.el
+++ b/lisp/emacs-lisp/backtrace.el
@@ -135,8 +135,7 @@ frames before its nearest activation frame are discarded."
 ;; Font Locking support
 
 (defconst backtrace--font-lock-keywords
-  '((backtrace--match-ellipsis-in-string
-     (1 'button prepend)))
+  '()
   "Expressions to fontify in Backtrace mode.
 Fontify these in addition to the expressions Emacs Lisp mode
 fontifies.")
@@ -154,16 +153,6 @@ fontifies.")
           backtrace--font-lock-keywords)
   "Gaudy level highlighting for Backtrace mode.")
 
-(defun backtrace--match-ellipsis-in-string (bound)
-  ;; Fontify ellipses within strings as buttons.
-  ;; This is necessary because ellipses are text property buttons
-  ;; instead of overlay buttons, which is done because there could
-  ;; be a large number of them.
-  (when (re-search-forward "\\(\\.\\.\\.\\)\"" bound t)
-    (and (get-text-property (- (point) 2) 'cl-print-ellipsis)
-         (get-text-property (- (point) 3) 'cl-print-ellipsis)
-         (get-text-property (- (point) 4) 'cl-print-ellipsis))))
-
 ;;; Xref support
 
 (defun backtrace--xref-backend () 'elisp)
@@ -424,12 +413,12 @@ the buffer."
       (overlay-put o 'evaporate t))))
 
 (defun backtrace--change-button-skip (beg end value)
-  "Change the skip property on all buttons between BEG and END.
-Set it to VALUE unless the button is a `backtrace-ellipsis' button."
+  "Change the `skip' property on all buttons between BEG and END.
+Set it to VALUE unless the button is a `cl-print-ellipsis' button."
   (let ((inhibit-read-only t))
     (setq beg (next-button beg))
     (while (and beg (< beg end))
-      (unless (eq (button-type beg) 'backtrace-ellipsis)
+      (unless (eq (button-type beg) 'cl-print-ellipsis)
           (button-put beg 'skip value))
       (setq beg (next-button beg)))))
 
@@ -497,34 +486,15 @@ Reprint the frame with the new view plist."
                          `(backtrace-index ,index backtrace-view ,view))
     (goto-char min)))
 
-(defun backtrace-expand-ellipsis (button)
-  "Expand display of the elided form at BUTTON."
-  (interactive)
-  (goto-char (button-start button))
-  (unless (get-text-property (point) 'cl-print-ellipsis)
-    (if (and (> (point) (point-min))
-             (get-text-property (1- (point)) 'cl-print-ellipsis))
-        (backward-char)
-      (user-error "No ellipsis to expand here")))
-  (let* ((end (next-single-property-change (point) 'cl-print-ellipsis))
-         (begin (previous-single-property-change end 'cl-print-ellipsis))
-         (value (get-text-property begin 'cl-print-ellipsis))
-         (props (backtrace-get-text-properties begin))
+(defun backtrace--expand-ellipsis (orig-fun begin end val _length &rest args)
+  "Wrapper to expand an ellipsis.
+For use on `cl-print-expand-ellipsis-function'."
+  (let* ((props (backtrace-get-text-properties begin))
          (inhibit-read-only t))
     (backtrace--with-output-variables (backtrace-get-view)
-      (delete-region begin end)
-      (insert (cl-print-to-string-with-limit #'cl-print-expand-ellipsis value
-                                          backtrace-line-length))
-      (setq end (point))
-      (goto-char begin)
-      (while (< (point) end)
-        (let ((next (next-single-property-change (point) 'cl-print-ellipsis
-                                                 nil end)))
-          (when (get-text-property (point) 'cl-print-ellipsis)
-            (make-text-button (point) next :type 'backtrace-ellipsis))
-          (goto-char next)))
-      (goto-char begin)
-      (add-text-properties begin end props))))
+      (let ((end (apply orig-fun begin end val backtrace-line-length args)))
+        (add-text-properties begin end props)
+        end))))
 
 (defun backtrace-expand-ellipses (&optional no-limit)
   "Expand display of all \"...\"s in the backtrace frame at point.
@@ -697,13 +667,6 @@ line and recenter window line accordingly."
                  (recenter window-line)))
       (goto-char (point-min)))))
 
-;; Define button type used for ...'s.
-;; Set skip property so you don't have to TAB through 100 of them to
-;; get to the next function name.
-(define-button-type 'backtrace-ellipsis
-  'skip t 'action #'backtrace-expand-ellipsis
-  'help-echo "mouse-2, RET: expand this ellipsis")
-
 (defun backtrace-print-to-string (obj &optional limit)
   "Return a printed representation of OBJ formatted for backtraces.
 Attempt to get the length of the returned string under LIMIT
@@ -720,15 +683,6 @@ characters with appropriate settings of `print-level' and
     (insert (cl-print-to-string-with-limit #'backtrace--print sexp limit))
     ;; Add a unique backtrace-form property.
     (put-text-property (point-min) (point) 'backtrace-form (gensym))
-    ;; Make buttons from all the "..."s.  Since there might be many of
-    ;; them, use text property buttons.
-    (goto-char (point-min))
-    (while (< (point) (point-max))
-      (let ((end (next-single-property-change (point) 'cl-print-ellipsis
-                                              nil (point-max))))
-        (when (get-text-property (point) 'cl-print-ellipsis)
-          (make-text-button (point) end :type 'backtrace-ellipsis))
-        (goto-char end)))
     (buffer-string)))
 
 (defun backtrace-print-frame (frame view)
@@ -919,6 +873,8 @@ followed by `backtrace-print-frame', once for each stack frame."
   (setq-local filter-buffer-substring-function #'backtrace--filter-visible)
   (setq-local indent-line-function 'lisp-indent-line)
   (setq-local indent-region-function 'lisp-indent-region)
+  (add-function :around (local 'cl-print-expand-ellipsis-function)
+                #'backtrace--expand-ellipsis)
   (add-hook 'xref-backend-functions #'backtrace--xref-backend nil t))
 
 (put 'backtrace-mode 'mode-class 'special)