diff options
Diffstat (limited to 'lisp/emacs-lisp/debug.el')
| -rw-r--r-- | lisp/emacs-lisp/debug.el | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/lisp/emacs-lisp/debug.el b/lisp/emacs-lisp/debug.el index 506b73f6fa2..ec947c1215d 100644 --- a/lisp/emacs-lisp/debug.el +++ b/lisp/emacs-lisp/debug.el @@ -153,6 +153,12 @@ where CAUSE can be: (insert (debugger--buffer-state-content state))) (goto-char (debugger--buffer-state-pos state))) +(defvar debugger--last-error nil) + +(defun debugger--duplicate-p (args) + (pcase args + (`(error ,err . ,_) (and (consp err) (eq err debugger--last-error))))) + ;;;###autoload (setq debugger 'debug) ;;;###autoload @@ -175,9 +181,14 @@ first will be printed into the backtrace buffer. If `inhibit-redisplay' is non-nil when this function is called, the debugger will not be entered." (interactive) - (if inhibit-redisplay - ;; Don't really try to enter debugger within an eval from redisplay. + (if (or inhibit-redisplay + (debugger--duplicate-p args)) + ;; Don't really try to enter debugger within an eval from redisplay + ;; or if we already popper into the debugger for this error, + ;; which can happen when we have several nested `handler-bind's that + ;; want to invoke the debugger. debugger-value + (setq debugger--last-error nil) (let ((non-interactive-frame (or noninteractive ;FIXME: Presumably redundant. ;; If we're in the initial-frame (where `message' just @@ -200,7 +211,7 @@ the debugger will not be entered." (let (debugger-value (debugger-previous-state (if (get-buffer "*Backtrace*") - (with-current-buffer (get-buffer "*Backtrace*") + (with-current-buffer "*Backtrace*" (debugger--save-buffer-state)))) (debugger-args args) (debugger-buffer (get-buffer-create "*Backtrace*")) @@ -318,6 +329,12 @@ the debugger will not be entered." (backtrace-mode)))) (with-timeout-unsuspend debugger-with-timeout-suspend) (set-match-data debugger-outer-match-data))) + (when (eq 'error (car-safe debugger-args)) + ;; Remember the error we just debugged, to avoid re-entering + ;; the debugger if some higher-up `handler-bind' invokes us + ;; again, oblivious that the error was already debugged from + ;; a more deeply nested `handler-bind'. + (setq debugger--last-error (nth 1 debugger-args))) (setq debug-on-next-call debugger-step-after-exit) debugger-value)))) @@ -651,7 +668,7 @@ Complete list of commands: (princ (debugger-eval-expression exp)) (terpri)) - (with-current-buffer (get-buffer debugger-record-buffer) + (with-current-buffer debugger-record-buffer (message "%s" (buffer-substring (line-beginning-position 0) (line-end-position 0))))) |