[O] Bug: check that org-element--cache-sync-keys is non-nil before clrhash [8.3.4 (8.3.4-42-gae73c7-elpa @ /home/mah/.emacs.d/elpa/org-20160425/)]

[Mark A. Hershberger]

Emacs  : GNU Emacs 24.4.1 (x86_64-pc-linux-gnu, GTK+ Version 3.14.5)
 of 2015-03-07 on trouble, modified by Debian
Package: Org-mode version 8.3.4 (8.3.4-42-gae73c7-elpa @ 
/home/mah/.emacs.d/elpa/org-20160425/)

I'm using org-mode by default for most buffers and, when using
gnus-alias-use-identity, I get a backtrace because
org-element--cache-sync-keys is set to nil.

Patch to fix this:

diff --git a/lisp/org-element.el b/lisp/org-element.el
index d02b36c..760fce8 100644
--- a/lisp/org-element.el
+++ b/lisp/org-element.el
@@ -5121,7 +5121,8 @@ updated before current modification are actually 
submitted."
        ;; Otherwise, reset keys.
        (if org-element--cache-sync-requests
            (org-element--cache-set-timer buffer)
-         (clrhash org-element--cache-sync-keys))))))
+         (when org-element--cache-sync-keys
+            (clrhash org-element--cache-sync-keys)))))))
 
 (defun org-element--cache-process-request
     (request next threshold time-limit future-change)


Edited backtrace:

Debugger entered--Lisp error: (wrong-type-argument hash-table-p nil)
  clrhash(nil)
  (if org-element--cache-sync-requests (org-element--cache-set-timer buffer) 
(clrhash org-element--cache-sync-keys))
  (let ((inhibit-quit t) request next) (if org-element--cache-sync-timer (progn 
(cancel-timer org-element--cache-sync-timer))) (catch (quote interrupt) (while 
org-element--cache-sync-requests (setq request (car 
org-element--cache-sync-requests) next (nth 1 
org-element--cache-sync-requests)) (org-element--cache-process-request request 
(and next (aref next 0)) threshold (and (not threshold) (time-add 
(current-time) org-element-cache-sync-duration)) future-change) (if next (progn 
(let* ((v next)) (aset v 3 (+ ... ...))) (aset next 2 (aref request 2)))) (setq 
org-element--cache-sync-requests (cdr org-element--cache-sync-requests)))) (if 
org-element--cache-sync-requests (org-element--cache-set-timer buffer) (clrhash 
org-element--cache-sync-keys)))
  (save-current-buffer (set-buffer buffer) (let ((inhibit-quit t) request next) 
(if org-element--cache-sync-timer (progn (cancel-timer 
org-element--cache-sync-timer))) (catch (quote interrupt) (while 
org-element--cache-sync-requests (setq request (car 
org-element--cache-sync-requests) next (nth 1 
org-element--cache-sync-requests)) (org-element--cache-process-request request 
(and next (aref next 0)) threshold (and (not threshold) (time-add 
(current-time) org-element-cache-sync-duration)) future-change) (if next (progn 
(let* (...) (aset v 3 ...)) (aset next 2 (aref request 2)))) (setq 
org-element--cache-sync-requests (cdr org-element--cache-sync-requests)))) (if 
org-element--cache-sync-requests (org-element--cache-set-timer buffer) (clrhash 
org-element--cache-sync-keys))))
  (progn (save-current-buffer (set-buffer buffer) (let ((inhibit-quit t) 
request next) (if org-element--cache-sync-timer (progn (cancel-timer 
org-element--cache-sync-timer))) (catch (quote interrupt) (while 
org-element--cache-sync-requests (setq request (car 
org-element--cache-sync-requests) next (nth 1 
org-element--cache-sync-requests)) (org-element--cache-process-request request 
(and next (aref next 0)) threshold (and (not threshold) (time-add ... 
org-element-cache-sync-duration)) future-change) (if next (progn (let* ... ...) 
(aset next 2 ...))) (setq org-element--cache-sync-requests (cdr 
org-element--cache-sync-requests)))) (if org-element--cache-sync-requests 
(org-element--cache-set-timer buffer) (clrhash org-element--cache-sync-keys)))))
  (if (buffer-live-p buffer) (progn (save-current-buffer (set-buffer buffer) 
(let ((inhibit-quit t) request next) (if org-element--cache-sync-timer (progn 
(cancel-timer org-element--cache-sync-timer))) (catch (quote interrupt) (while 
org-element--cache-sync-requests (setq request (car 
org-element--cache-sync-requests) next (nth 1 
org-element--cache-sync-requests)) (org-element--cache-process-request request 
(and next ...) threshold (and ... ...) future-change) (if next (progn ... ...)) 
(setq org-element--cache-sync-requests (cdr 
org-element--cache-sync-requests)))) (if org-element--cache-sync-requests 
(org-element--cache-set-timer buffer) (clrhash 
org-element--cache-sync-keys))))))
  org-element--cache-sync(#<buffer Re: [hexmode/xml-rpc-el] St...<2>>)
  apply(org-element--cache-sync #<buffer Re: [hexmode/xml-rpc-el] St...<2>>)
  byte-code("r\301\302H\303H\"\210)\301\207" [timer apply 5 6] 4)
  timer-event-handler([t 0 0 600000 nil org-element--cache-sync (#<buffer Re: 
[hexmode/xml-rpc-el] St...<2>>) idle 0])
  read-from-minibuffer("Identity: " nil ...)
  completing-read-default("Identity: " ...)
  completing-read("Identity: " ...)
  gnus-alias-identity-prompt()
  gnus-alias-use-identity()
[SNIP]