1 files changed, 44 insertions, 29 deletions

diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 70d0fb070d8..a38b3c6e51c 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -3621,8 +3621,13 @@ support symbolic links."
          (output-buffer-p output-buffer)
          (output-buffer
           (cond
-           ((bufferp output-buffer) output-buffer)
-           ((stringp output-buffer) (get-buffer-create output-buffer))
+           ((bufferp output-buffer)
+            (setq current-buffer-p (eq (current-buffer) output-buffer))
+            output-buffer)
+           ((stringp output-buffer)
+            (setq current-buffer-p
+                  (eq (buffer-name (current-buffer)) output-buffer))
+            (get-buffer-create output-buffer))
            (output-buffer
             (setq current-buffer-p t)
             (current-buffer))
@@ -3634,6 +3639,11 @@ support symbolic links."
           (cond
            ((bufferp error-buffer) error-buffer)
            ((stringp error-buffer) (get-buffer-create error-buffer))))
+         (error-file
+          (and error-buffer
+               (with-parsed-tramp-file-name default-directory nil
+                 (tramp-make-tramp-file-name
+                  v (tramp-make-tramp-temp-file v)))))
          (bname (buffer-name output-buffer))
          (p (get-buffer-process output-buffer))
          (dir default-directory)
@@ -3641,7 +3651,7 @@ support symbolic links."
 
     ;; The following code is taken from `shell-command', slightly
     ;; adapted.  Shouldn't it be factored out?
-    (when p
+    (when (and (integerp asynchronous) p)
       (cond
        ((eq async-shell-command-buffer 'confirm-kill-process)
         ;; If will kill a process, query first.
@@ -3677,22 +3687,21 @@ support symbolic links."
       (with-current-buffer output-buffer
         (setq default-directory dir)))
 
-    (setq buffer (if error-buffer
-                     (with-parsed-tramp-file-name default-directory nil
-                       (list output-buffer
-                             (tramp-make-tramp-file-name
-                              v (tramp-make-tramp-temp-file v))))
-                   output-buffer))
-
-    (if current-buffer-p
-        (progn
-          (barf-if-buffer-read-only)
-          (push-mark nil t))
-      (with-current-buffer output-buffer
+    (setq buffer (if error-file (list output-buffer error-file) output-buffer))
+
+    (with-current-buffer output-buffer
+      (when current-buffer-p
+        (barf-if-buffer-read-only)
+        (push-mark nil t))
+      ;; `shell-command-save-pos-or-erase' has been introduced with
+      ;; Emacs 27.1.
+      (if (fboundp 'shell-command-save-pos-or-erase)
+          (tramp-compat-funcall
+           'shell-command-save-pos-or-erase current-buffer-p)
         (setq buffer-read-only nil)
         (erase-buffer)))
 
-    (if (and (not current-buffer-p) (integerp asynchronous))
+    (if (integerp asynchronous)
         (let ((tramp-remote-process-environment
                ;; `async-shell-command-width' has been introduced with
                ;; Emacs 27.1.
@@ -3706,9 +3715,9 @@ support symbolic links."
               (setq p (start-file-process-shell-command
                        (buffer-name output-buffer) buffer command))
             ;; Insert error messages if they were separated.
-            (when (consp buffer)
+            (when error-file
               (with-current-buffer error-buffer
-                (insert-file-contents-literally (cadr buffer))))
+                (insert-file-contents-literally error-file)))
             (if (process-live-p p)
               ;; Display output.
               (with-current-buffer output-buffer
@@ -3717,34 +3726,40 @@ support symbolic links."
                 (shell-mode)
                 (set-process-filter p #'comint-output-filter)
                 (set-process-sentinel p #'shell-command-sentinel)
-                (when (consp buffer)
+                (when error-file
                   (add-function
                    :after (process-sentinel p)
                    (lambda (_proc _string)
                      (with-current-buffer error-buffer
                        (insert-file-contents-literally
-                        (cadr buffer) nil nil nil 'replace))
-                     (delete-file (cadr buffer))))))
+                        error-file nil nil nil 'replace))
+                     (delete-file error-file)))))
 
-              (when (consp buffer)
-                (delete-file (cadr buffer))))))
+              (when error-file
+                (delete-file error-file)))))
 
       (prog1
           ;; Run the process.
           (process-file-shell-command command nil buffer nil)
         ;; Insert error messages if they were separated.
-        (when (consp buffer)
+        (when error-file
           (with-current-buffer error-buffer
-            (insert-file-contents-literally (cadr buffer)))
-          (delete-file (cadr buffer)))
+            (insert-file-contents-literally error-file))
+          (delete-file error-file))
         (if current-buffer-p
             ;; This is like exchange-point-and-mark, but doesn't
             ;; activate the mark.  It is cleaner to avoid activation,
             ;; even though the command loop would deactivate the mark
             ;; because we inserted text.
-            (goto-char (prog1 (mark t)
-                         (set-marker (mark-marker) (point)
-                                     (current-buffer))))
+            (progn
+              (goto-char (prog1 (mark t)
+                           (set-marker (mark-marker) (point)
+                                       (current-buffer))))
+              ;; `shell-command-set-point-after-cmd' has been
+              ;; introduced with Emacs 27.1.
+              (if (fboundp 'shell-command-set-point-after-cmd)
+                  (tramp-compat-funcall
+                   'shell-command-set-point-after-cmd)))
           ;; There's some output, display it.
           (when (with-current-buffer output-buffer (> (point-max) (point-min)))
             (display-message-or-buffer output-buffer)))))))