[O] Bug: URL links in source block cause export to fall in infinite loop [7.9.3f (release_7.9.3f-17-g7524ef @ /usr/local/share/emacs/24.3.50/lisp/org/)]

[Andrey Kotlarski]

Here are steps to reproduce with trunk version of GNU Emacs:

1. emacs -Q

2. C-x b test

3. M-x org-mode

4. Insert the following:

#+begin_src sh
"http://";
#+end_src

5. C-c C-e H

That's it, export blocks and only C-g takes is out of the loop.

I tried with several source block languages with identical behaviour.  I
bisected bazaar for where this bug has been introduced:

111688: Glenn Morris 2013-02-07 [merge] Merge from emacs-24; up to
r111231

It exports successfully before that.

Emacs  : GNU Emacs 24.3.50.2 (x86_64-fedora-linux-gnu)
 of 2013-03-01 on ws-akotlarski.sf.vayant.com
Package: Org-mode version 7.9.3f (release_7.9.3f-17-g7524ef @ 
/usr/local/share/emacs/24.3.50/lisp/org/)

current state:
==============
(setq
 org-export-preprocess-before-selecting-backend-code-hook 
'(org-beamer-select-beamer-code)
 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-export-preprocess-before-normalizing-links-hook 
'(org-remove-file-link-modifiers)
 org-confirm-shell-link-function 'yes-or-no-p
 org-export-latex-final-hook '(org-beamer-amend-header org-beamer-fix-toc
                               org-beamer-auto-fragile-frames
                               org-beamer-place-default-actions-for-lists)
 org-export-latex-after-initial-vars-hook '(org-beamer-after-initial-vars)
 org-after-todo-state-change-hook '(org-clock-out-if-current)
 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-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-show-empty-lines 
org-optimize-window-after-visibility-change)
 org-export-latex-format-toc-function 'org-export-latex-format-toc-default
 org-export-blocks '((src org-babel-exp-src-block nil)
                     (export-comment org-export-blocks-format-comment t)
                     (ditaa org-export-blocks-format-ditaa nil)
                     (dot org-export-blocks-format-dot nil))
 org-export-first-hook '(org-beamer-initialize-open-trackers)
 org-export-interblocks '((src org-babel-exp-non-block-elements))
 org-confirm-elisp-link-function 'yes-or-no-p
 org-metadown-hook '(org-babel-pop-to-session-maybe)
 org-clock-out-hook '(org-clock-remove-empty-clock-drawer)
 )