(tar-extract): Base the name of the subfile buffer

on the name of the tar buffer.  Verify that the existing buffer is
visiting the same subfile.

diff --git a/lisp/tar-mode.el b/lisp/tar-mode.el
index 5c5bdae417017cdeadf0b0570bb6cdacf1778d46..264bc37f2e62d37509823bf4f97519cd45921cff 100644 (file)
--- a/lisp/tar-mode.el
+++ b/lisp/tar-mode.el
@@ -678,19 +678,23 @@ appear on disk when you save the tar-file's buffer."
         (end (+ start size)))
     (let* ((tar-buffer (current-buffer))
           (tar-buffer-multibyte enable-multibyte-characters)
-          (tarname (if (buffer-file-name)
-                       (file-name-nondirectory (buffer-file-name))
-                     (buffer-name)))
+          (tarname (buffer-name))
           (bufname (concat (file-name-nondirectory name)
                            " ("
                            tarname
                            ")"))
           (read-only-p (or buffer-read-only view-p))
           (buffer (get-buffer bufname))
-          (just-created nil))
-      (if buffer
+          (just-created nil)
+          (new-buffer-file-name (expand-file-name
+                                 ;; `:' is not allowed on Windows
+                                 (concat tarname "!" name))))
+      (if (and buffer
+              ;; Check that the buffer is visiting the same file
+              (equal (buffer-file-name buffer) new-buffer-file-name))
          nil
-       (setq buffer (get-buffer-create bufname))
+       (setq buffer (generate-new-buffer bufname))
+       (setq bufname (buffer-name buffer))
        (setq just-created t)
        (unwind-protect
            (progn
@@ -706,9 +710,7 @@ appear on disk when you save the tar-file's buffer."
                      (set-buffer-multibyte t))
                  (insert-buffer-substring tar-buffer start end))
                (goto-char (point-min))
-               (setq buffer-file-name
-                     ;; `:' is not allowed on Windows
-                     (expand-file-name (concat tarname "!" name)))
+               (setq buffer-file-name new-buffer-file-name)
                (setq buffer-file-truename
                      (abbreviate-file-name buffer-file-name))
                ;; We need to mimic the parts of insert-file-contents