Regression in Org triggered from helm

[Simon Thum <simon.thum@gmx.de>]

Hi,

after updating helm I came across a possible regression on Org. I 
Already filed a helm bug, but Thierry thinks it's Org's fault.

https://github.com/emacs-helm/helm/issues/1246

In short, M-x helm-org-agenda-files-headings breaks.

I had some success working around it, but for reasons beyond me that 
doesn't work any more. I'll try to work out a MCE but for the time in 
between, maybe someone has an idea what's wrong, and where (org or helm)?

Here is the complete stacktrace (the -my function is textually 
equivalent to its non-my counterpart in helm-org):


Debugger entered--Lisp error: (args-out-of-range "LoD" 0 -3)
   substring("LoD" 0 -6)
   (setq h (substring h 0 (- maxwidth 2)) total (+ total maxwidth 1))
   (if (< (length h) maxwidth) (progn (setq total (+ total (length h) 
1)) h) (setq h (substring h 0 (- maxwidth 2)) total (+ total maxwidth 
1)) (if (string-match "[ 	]+\\'" h) (setq h (substring h 0 
(match-beginning 0)))) (setq h (concat h "..")))
   (lambda (h) (setq n (1+ n)) (if (and (= n nsteps) (< maxwidth 10000)) 
(setq maxwidth (- total-width total))) (if (< (length h) maxwidth) 
(progn (setq total (+ total (length h) 1)) h) (setq h (substring h 0 (- 
maxwidth 2)) total (+ total maxwidth 1)) (if (string-match "[ 	]+\\'" h) 
(setq h (substring h 0 (match-beginning 0)))) (setq h (concat h ".."))) 
(org-add-props h nil (quote face) (nth (% (1- n) org-n-level-faces) 
org-level-faces)) h)("LoD")
   mapconcat((lambda (h) (setq n (1+ n)) (if (and (= n nsteps) (< 
maxwidth 10000)) (setq maxwidth (- total-width total))) (if (< (length 
h) maxwidth) (progn (setq total (+ total (length h) 1)) h) (setq h 
(substring h 0 (- maxwidth 2)) total (+ total maxwidth 1)) (if 
(string-match "[ 	]+\\'" h) (setq h (substring h 0 (match-beginning 
0)))) (setq h (concat h ".."))) (org-add-props h nil (quote face) (nth 
(% (1- n) org-n-level-faces) org-level-faces)) h) (#("CityServer3D" 0 12 
(face org-level-1)) #("Archive" 0 7 (face org-level-2)) #("Portrayal" 0 
9 (face org-level-3)) #("Konzeption" 0 10 (face org-level-4)) 
#("Symbolizer" 0 10 (face org-level-5)) "Einsatzgebiete" "LoD") "/")
   (concat prefix (if prefix (or separator "/")) (mapconcat (function 
(lambda (h) (setq n (1+ n)) (if (and (= n nsteps) (< maxwidth 10000)) 
(setq maxwidth (- total-width total))) (if (< (length h) maxwidth) 
(progn (setq total (+ total ... 1)) h) (setq h (substring h 0 (- 
maxwidth 2)) total (+ total maxwidth 1)) (if (string-match "[ 	]+\\'" h) 
(setq h (substring h 0 ...))) (setq h (concat h ".."))) (org-add-props h 
nil (quote face) (nth (% (1- n) org-n-level-faces) org-level-faces)) h)) 
path (or separator "/")))
   (let* ((nsteps (length path)) (total-width (+ nsteps (apply (quote +) 
(mapcar (quote length) path)))) (maxwidth (if (<= total-width width) 
10000 (/ (- width nsteps) nsteps))) (org-odd-levels-only nil) (n 0) 
(total (1+ (length prefix)))) (setq maxwidth (max maxwidth 10)) (concat 
prefix (if prefix (or separator "/")) (mapconcat (function (lambda (h) 
(setq n (1+ n)) (if (and (= n nsteps) (< maxwidth 10000)) (setq maxwidth 
(- total-width total))) (if (< (length h) maxwidth) (progn (setq total 
...) h) (setq h (substring h 0 ...) total (+ total maxwidth 1)) (if 
(string-match "[ 	]+\\'" h) (setq h ...)) (setq h (concat h ".."))) 
(org-add-props h nil (quote face) (nth (% ... org-n-level-faces) 
org-level-faces)) h)) path (or separator "/"))))
   (if (not path) (or prefix "") (let* ((nsteps (length path)) 
(total-width (+ nsteps (apply (quote +) (mapcar (quote length) path)))) 
(maxwidth (if (<= total-width width) 10000 (/ (- width nsteps) nsteps))) 
(org-odd-levels-only nil) (n 0) (total (1+ (length prefix)))) (setq 
maxwidth (max maxwidth 10)) (concat prefix (if prefix (or separator 
"/")) (mapconcat (function (lambda (h) (setq n (1+ n)) (if (and ... ...) 
(setq maxwidth ...)) (if (< ... maxwidth) (progn ... h) (setq h ... 
total ...) (if ... ...) (setq h ...)) (org-add-props h nil (quote face) 
(nth ... org-level-faces)) h)) path (or separator "/")))))
   org-format-outline-path((#("CityServer3D" 0 12 (face org-level-1)) 
#("Archive" 0 7 (face org-level-2)) #("Portrayal" 0 9 (face 
org-level-3)) #("Konzeption" 0 10 (face org-level-4)) #("Symbolizer" 0 
10 (face org-level-5)) "Einsatzgebiete" "LoD") 80 "projects.org:")
 
helm-get-org-candidates-in-file("/home/simon/org/fraunhofer/projects.org" 1 
8 nil nil)
   #[257 "\304\x01\300\301\n\v%\207" [1 8 helm-org-headings-fontify 
helm-org-headings--nofilename helm-get-org-candidates-in-file] 7 
"\n\n(fn FILENAME)"]("/home/simon/org/fraunhofer/projects.org")
   mapcar(#[257 "\304\x01\300\301\n\v%\207" [1 8 helm-org-headings-fontify 
helm-org-headings--nofilename helm-get-org-candidates-in-file] 7 
"\n\n(fn FILENAME)"] ("/home/simon/org/....org"))
   helm-org-get-candidates(("/home/simon/org/....org") 1 8)
   helm-source-org-headings-for-files(("/home/simon/org/....org"))
   helm-org-agenda-files-headings()
   call-interactively(helm-org-agenda-files-headings record nil)
   command-execute(helm-org-agenda-files-headings record)
   execute-extended-command(nil "helm-org-agenda-files-headings")
   call-interactively(execute-extended-command nil nil)
   command-execute(execute-extended-command)