emacs-28 07edc28: Fix ert errors when there's a test that binds `debug-on-error'

[Lars Ingebrigtsen]

branch: emacs-28
commit 07edc28bdbfeeaeb1008b4fe21bfda586feae562
Author: Lars Ingebrigtsen <larsi@gnus.org>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Fix ert errors when there's a test that binds `debug-on-error'
    
    * lisp/emacs-lisp/ert.el (ert--run-test-internal): Don't infloop
    on errors when signalling errors (bug#51131).
---
 lisp/emacs-lisp/ert.el | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lisp/emacs-lisp/ert.el b/lisp/emacs-lisp/ert.el
index 98cb1fd..b7d9843 100644
--- a/lisp/emacs-lisp/ert.el
+++ b/lisp/emacs-lisp/ert.el
@@ -783,6 +783,10 @@ This mainly sets up debugger-related bindings."
                           (ert--run-test-debugger test-execution-info
                                                   args)))
               (debug-on-error t)
+              ;; Don't infloop if the error being called is erroring
+              ;; out, and we have `debug-on-error' bound to nil inside
+              ;; the test.
+              (backtrace-on-error-noninteractive nil)
               (debug-on-quit t)
               ;; FIXME: Do we need to store the old binding of this
               ;; and consider it in `ert--run-test-debugger'?