Backport: Fix bug 39218

* lisp/simple.el (shell-command):
Ensure a shell command ending with `&' is run asynchronously.

1 files changed, 2 insertions, 1 deletions

diff --git a/lisp/simple.el b/lisp/simple.el
index 3546bef600d..73aea415c77 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -3640,10 +3640,11 @@ impose the use of a shell (with its need to quote arguments)."
     (if handler
         (funcall handler 'shell-command command output-buffer error-buffer)
       (if (and output-buffer
+               (not (string-match "[ \t]*&[ \t]*\\'" command))
                (or (eq output-buffer (current-buffer))
                    (and (stringp output-buffer) (eq (get-buffer output-buffer) (current-buffer)))
                    (not (or (bufferp output-buffer) (stringp output-buffer))))) ; Bug#39067
-          ;; Output goes in current buffer.
+          ;; Synchronous command with output in current buffer.
           (let ((error-file
                  (and error-buffer
                       (make-temp-file