bug#55863: 29.0.50; [PATCH] Avoid hanging chad of *Backtrace*

[Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

dick.r.chiang@gmail.com writes:

> Subject: [PATCH] Avoid the hanging chad of "*Backtrace*"

Most people do not use paper punches anymore, and are likely to think of
the urban slang meaning of "chad" instead.  Mysterious commit messages
do not belong in our source code.

> * lisp/emacs-lisp/debug.el (debugger-buffer-name): DRY.
> (debug): Don't just erase the *Backtrace*; kill it.
> * test/lisp/abbrev-tests.el (copy-abbrev-table-test):
> We have `ignore-errors` for this purpose.
> (abbrev-tests-backtrace-bury): Test it.
> ---
>  lisp/emacs-lisp/debug.el  | 113 ++++++++++++++++++--------------------
>  test/lisp/abbrev-tests.el |  20 +++++--

So exactly what is the problem, and where is the fix?  And why is
`abbrev-tests.el' related?

>  2 files changed, 68 insertions(+), 65 deletions(-)
>
> diff --git a/lisp/emacs-lisp/debug.el b/lisp/emacs-lisp/debug.el
> index 6c172d6c31d..c1c977ce66e 100644
> --- a/lisp/emacs-lisp/debug.el
> +++ b/lisp/emacs-lisp/debug.el
> @@ -95,6 +95,8 @@ debug-allow-recursive-debug
>    :type 'boolean
>    :version "29.1")
>  
> +(defconst debugger-buffer-name "*Backtrace*")

No doc string.