bug#30051: 27.0.50; diary-lib.el uses lexical scoping when dynamic scope is needed

[Glenn Morris]

Hi Stefan, please could you take a look at this report.
I can't personally reproduce an error, due to appt-check's use of
ignore-errors, but indeed it no longer seems to work.

Richard Kim wrote:

> I started getting the following error from recently compiled emacs:
>
>     Debugger entered--Lisp error: (void-variable number)
>     appt-make-list()
>     run-hooks(diary-hook)
>     diary-list-entries((1 8 2018) 1)
>     org-get-entries-from-diary((1 8 2018))
>     org-agenda-list(nil)
>     funcall-interactively(org-agenda-list nil)
>     call-interactively(org-agenda-list)
>     (let nil (call-interactively 'org-agenda-list))
>     (let nil (let nil (call-interactively 'org-agenda-list)))
>     eval((let nil (let nil (call-interactively 'org-agenda-list))))
>     org-let2(nil nil (call-interactively 'org-agenda-list))
>     org-agenda-run-series("Agenda and all TODOs" (((agenda "") (alltodo ""))))
>     eval((org-agenda-run-series "Agenda and all TODOs" '(((agenda "") 
> (alltodo "")))))
>     org-agenda-redo(nil)
>     funcall-interactively(org-agenda-redo nil)
>     call-interactively(org-agenda-redo nil nil)
>     command-execute(org-agenda-redo)
>
> This appears to be due to using lexical binding for diary-lib.el.
>
> diary-list-entries is defined in diary-lib.el which uses lexical-binding as
> of master branch change 559d685f68 checked in on 2017/12/04.
> However appt-make-list depends on dynamically scoped `number' variable
> to be defined by diary-list-entries as documented in the doc-string:
>
>     We assume that the variables DATE and NUMBER hold the arguments that
>     `diary-list-entries' received.
>
> In GNU Emacs 27.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 2.24.23)
>  of 2017-12-28 built on rutro-int1
> Repository revision: ace8f2ed4d6ea49d179333f8e7455e5208417da7