Don't remember old debugger window (Bug#17882)

* lisp/emacs-lisp/debug.el (debug): Unset debugger-previous-window
when `debugger-will-be-back' is nil.

diff --git a/lisp/emacs-lisp/debug.el b/lisp/emacs-lisp/debug.el
index 0247179a843f9e8fc618f16df8befdba8bfca16f..6c754615b002470ea9d3a775e18daeb12ccf3395 100644 (file)
--- a/lisp/emacs-lisp/debug.el
+++ b/lisp/emacs-lisp/debug.el
@@ -253,7 +253,9 @@ first will be printed into the backtrace buffer."
                ;; Unshow debugger-buffer.
                (quit-restore-window debugger-window debugger-bury-or-kill)
                ;; Restore current buffer (Bug#12502).
-               (set-buffer debugger-old-buffer))))
+               (set-buffer debugger-old-buffer)))
+            ;; Forget debugger window, it won't be back (Bug#17882).
+            (setq debugger-previous-window nil))
           ;; Restore previous state of debugger-buffer in case we were
           ;; in a recursive invocation of the debugger, otherwise just
           ;; erase the buffer and put it into fundamental mode.