"Variable binding depth exceeds max-specpdl-size" behavior induced by footnotes [8.2.10 (release_8.2.10 @ /usr/local/share/emacs/24.5/lisp/org/)]

[Alexander Huang <x-o-o@o-o-x.com>]

* description

using the example below, calling =org-html-export-as-html= leads to a 
=mapc: Variable binding depth exceeds max-specpdl-size= error.

#+BEGIN_SRC org :file example-file.org

# must be non-leading
x[fn:A]

# must be leading
[fn:A]

# must be non-leading
x[fn:B]

# must be non-leading, and non-"a" entry
x[fn:B]

#+END_SRC

This seems to be the smallest I can make this example. To reproduce this 
error, the minimal file needs these properties:

1. at least 2 distinct footnote references
2. 1 of those footnotes is referenced (not leading) least 2 times
3. the actual footnote (in leading position) in step 2 must be 
sandwiched between references to it in non-leading positions
4. the first reference (non-leading) to the next unique footnote must 
occur before its definition (leading).

Thus, the export completes if either:
- the leading =[fn:A]= definition appears before the first =x[fn:A]= or 
after the second =x[fn:A]=
- =x[fn:B]= above is preceded by a leading =[fn:B]= (then the ordering 
of [fn:A] does not matter)

I have set =max-specpdl-size= and =max-lisp-eval-depth= to 20000+, 
though I believe this is unrelated.

This appears similar to

https://lists.gnu.org/archive/html/emacs-orgmode/2015-07/msg00079.html

But as far as I can tell it is different. I have not looked at the 
footnote code.


Emacs  : GNU Emacs 24.5.1 (x86_64-unknown-linux-gnu)
  of 2015-12-27 on localhost
Package: Org-mode version 8.2.10 (release_8.2.10 @ 
/usr/local/share/emacs/24.5/lisp/org/)

current state:
==============
(setq
  org-tab-first-hook '(org-hide-block-toggle-maybe 
org-src-native-tab-command-maybe
               org-babel-hide-result-toggle-maybe
               org-babel-header-arg-expand)
  org-speed-command-hook '(org-speed-command-default-hook
               org-babel-speed-command-hook)
  org-occur-hook '(org-first-headline-recenter)
  org-metaup-hook '(org-babel-load-in-session-maybe)
  org-html-format-drawer-function '(lambda (name contents) contents)
  org-latex-format-inlinetask-function 'ignore
  org-confirm-shell-link-function 'yes-or-no-p
  org-ascii-format-inlinetask-function 'org-ascii-format-inlinetask-default
  org-latex-format-headline-function 
'org-latex-format-headline-default-function
  org-after-todo-state-change-hook '(org-clock-out-if-current)
  org-latex-format-drawer-function '(lambda (name contents) contents)
  org-src-mode-hook '(org-src-babel-configure-edit-buffer
              org-src-mode-configure-edit-buffer)
  org-agenda-before-write-hook '(org-agenda-add-entry-text)
  org-babel-pre-tangle-hook '(save-buffer)
  org-mode-hook '(#[nil "\300\301\302\303\304$\207"
            [org-add-hook change-major-mode-hook org-show-block-all append
             local]
            5]
          #[nil "\300\301\302\303\304$\207"
            [org-add-hook change-major-mode-hook org-babel-show-result-all
             append local]
            5]
          org-babel-result-hide-spec org-babel-hide-all-hashes)
  org-ascii-format-drawer-function '(lambda (name contents width) contents)
  org-ctrl-c-ctrl-c-hook '(org-babel-hash-at-point 
org-babel-execute-safely-maybe)
  org-cycle-hook '(org-cycle-hide-archived-subtrees org-cycle-hide-drawers
           org-cycle-hide-inline-tasks org-cycle-show-empty-lines
           org-optimize-window-after-visibility-change)
  org-confirm-elisp-link-function 'yes-or-no-p
  org-metadown-hook '(org-babel-pop-to-session-maybe)
  org-html-format-headline-function 'ignore
  org-html-format-inlinetask-function 'ignore
  org-clock-out-hook '(org-clock-remove-empty-clock-drawer)
  )