Backport regexp stack overflow fix from emacs-24.

* textmodes/reftex-parse.el (reftex-using-biblatex-p): Make search
for comment lines non-greedy and stopping at newlines to fix stack
overflows with large files. [Backport]
Signed-off-by: Tassilo Horn <tsdh@gnu.org>

lisp/ChangeLog

+2014-11-27  Leonard Randall  <leonard.a.randall@gmail.com>
+
+	* textmodes/reftex-parse.el (reftex-using-biblatex-p): Make search
+	for comment lines non-greedy and stopping at newlines to fix stack
+	overflows with large files. [Backport]
+
 2014-11-27  Fabián Ezequiel Gallina  <fgallina@gnu.org>
 
 	* progmodes/python.el (python-shell-completion-setup-code): Use

lisp/textmodes/reftex-parse.el

@@ -357,7 +357,7 @@ of master file."
       (member "biblatex" TeX-active-styles)
     ;; poor-man's check...
     (save-excursion
-      (re-search-forward "^[^%]*\\\\usepackage.*{biblatex}" nil t))))
+      (re-search-forward "^[^%\n]*?\\\\usepackage.*{biblatex}" nil t))))
 
 (defun reftex-locate-bibliography-files (master-dir &optional files)
   "Scan buffer for bibliography macros and return file list."