Bug: fontification error with #end_src in 9.3.7 [9.3.7 (9.3.7-dist @ /PATH/TO/org/install/emacs/site-lisp/org/)]

[John Ciolfi]

Given the following org file, on the #+end_src line, I get "Org mode 
fontification error in #<buffer foo.org> at 9". If I place a newline before the 
#+end_src line, the error goes away. This is a recent regression. This worked 
fine in 9.2.6 and prior.

  #+begin_src C++
    #include <iostream>
    int main() {
        std::cout << "hello";
        return 0;
    }

    // The results:
  #+end_src

  #+RESULTS:



Emacs  : GNU Emacs 26.1 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.5)
 of 2019-09-22, modified by Debian
Package: Org mode version 9.3.7 (9.3.7-dist @ 
/PATH/TO/org/install/emacs/site-lisp/org/)

current state:
==============
(setq
 org-src-mode-hook '(org-src-babel-configure-edit-buffer 
org-src-mode-configure-edit-buffer)
 org-link-shell-confirm-function 'yes-or-no-p
 org-metadown-hook '(org-babel-pop-to-session-maybe)
 org-clock-out-hook '(org-clock-remove-empty-clock-drawer)
 org-latex-default-packages-alist 
'(("colorlinks=true,linkcolor={red!50!black},citecolor={blue!50!black},urlcolor={blue!80!black}"
 "hyperref" nil)
                                    ("AUTO" "inputenc" t ("pdflatex"))
                                    ("T1" "fontenc" t ("pdflatex")) ("" 
"graphicx" t)
                                    ("" "grffile" t) ("" "longtable" nil) ("" 
"wrapfig" nil)
                                    ("" "rotating" nil) ("normalem" "ulem" t) 
("" "amsmath" t)
                                    ("" "textcomp" t) ("" "amssymb" t) ("" 
"capt-of" nil)
                                    ("" "hyperref" nil))
 org-mode-hook '(#[0 "\300\301\302\303\304$\207"
                   [add-hook change-major-mode-hook org-show-all append local] 
5]
                 #[0 "\300\301\302\303\304$\207"
                   [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-archive-hook '(org-attach-archive-delete-maybe)
 org-confirm-elisp-link-function 'yes-or-no-p
 org-agenda-before-write-hook '(org-agenda-add-entry-text)
 org-metaup-hook '(org-babel-load-in-session-maybe)
 org-bibtex-headline-format-function #[257 "\300\236A\207" [:title] 3 "\n\n(fn 
ENTRY)"]
 org-babel-pre-tangle-hook '(save-buffer)
 org-tab-first-hook '(org-babel-hide-result-toggle-maybe 
org-babel-header-arg-expand)
 org-link-file-path-type 'relative
 org-occur-hook '(org-first-headline-recenter)
 org-cycle-hook '(org-cycle-hide-archived-subtrees org-cycle-show-empty-lines
                  org-optimize-window-after-visibility-change)
 org-speed-command-hook '(org-speed-command-activate 
org-babel-speed-command-activate)
 org-babel-tangle-lang-exts '(("perl" . "pl") ("D" . "d") ("C++" . "cpp") 
("emacs-lisp" . "el")
                              ("elisp" . "el"))
 org-confirm-shell-link-function 'yes-or-no-p
 org-link-parameters '(("attachment" :follow org-attach-open-link :export 
org-attach-export-link
                        :complete org-attach-complete-link)
                       ("id" :follow org-id-open) ("eww" :follow eww :store 
org-eww-store-link)
                       ("rmail" :follow org-rmail-open :store 
org-rmail-store-link)
                       ("mhe" :follow org-mhe-open :store org-mhe-store-link)
                       ("irc" :follow org-irc-visit :store org-irc-store-link 
:export
                        org-irc-export)
                       ("info" :follow org-info-open :export org-info-export 
:store
                        org-info-store-link)
                       ("gnus" :follow org-gnus-open :store org-gnus-store-link)
                       ("docview" :follow org-docview-open :export 
org-docview-export :store
                        org-docview-store-link)
                       ("bibtex" :follow org-bibtex-open :store 
org-bibtex-store-link)
                       ("bbdb" :follow org-bbdb-open :export org-bbdb-export 
:complete
                        org-bbdb-complete-link :store org-bbdb-store-link)
                       ("w3m" :store org-w3m-store-link) ("file+sys") 
("file+emacs")
                       ("shell" :follow org-link--open-shell)
                       ("news" :follow
                        #[257 "\301\300\302Q!\207" ["news" browse-url ":"] 5 
"\n\n(fn URL)"])
                       ("mailto" :follow
                        #[257 "\301\300\302Q!\207" ["mailto" browse-url ":"] 5 
"\n\n(fn URL)"])
                       ("https" :follow
                        #[257 "\301\300\302Q!\207" ["https" browse-url ":"] 5 
"\n\n(fn URL)"])
                       ("http" :follow
                        #[257 "\301\300\302Q!\207" ["http" browse-url ":"] 5 
"\n\n(fn URL)"])
                       ("ftp" :follow
                        #[257 "\301\300\302Q!\207" ["ftp" browse-url ":"] 5 
"\n\n(fn URL)"])
                       ("help" :follow org-link--open-help)
                       ("file" :complete org-link-complete-file)
                       ("elisp" :follow org-link--open-elisp) ("doi" :follow 
org-link--open-doi))
 org-link-elisp-confirm-function 'yes-or-no-p
 org-list-indent-offset 2
 )