+(defun gnus-recursive-directory-files (dir)
+ "Return all regular files below DIR."
+ (let (files)
+ (dolist (file (directory-files dir t))
+ (when (and (not (member (file-name-nondirectory file) '("." "..")))
+ (file-readable-p file))
+ (cond
+ ((file-regular-p file)
+ (push file files))
+ ((file-directory-p file)
+ (setq files (append (gnus-recursive-directory-files file) files))))))
+ files))
+
+(defun gnus-list-memq-of-list (elements list)
+ "Return non-nil if any of the members of ELEMENTS are in LIST."
+ (let ((found nil))
+ (dolist (elem elements)
+ (setq found (or found
+ (memq elem list))))
+ found))
+
+(eval-and-compile
+ (cond
+ ((fboundp 'match-substitute-replacement)
+ (defalias 'gnus-match-substitute-replacement 'match-substitute-replacement))
+ (t
+ (defun gnus-match-substitute-replacement (replacement &optional fixedcase literal string subexp)
+ "Return REPLACEMENT as it will be inserted by `replace-match'.
+In other words, all back-references in the form `\\&' and `\\N'
+are substituted with actual strings matched by the last search.
+Optional FIXEDCASE, LITERAL, STRING and SUBEXP have the same
+meaning as for `replace-match'.
+
+This is the definition of match-substitute-replacement in subr.el from GNU Emacs."
+ (let ((match (match-string 0 string)))
+ (save-match-data
+ (set-match-data (mapcar (lambda (x)
+ (if (numberp x)
+ (- x (match-beginning 0))
+ x))
+ (match-data t)))
+ (replace-match replacement fixedcase literal match subexp)))))))
+
+(if (fboundp 'string-match-p)
+ (defalias 'gnus-string-match-p 'string-match-p)
+ (defsubst gnus-string-match-p (regexp string &optional start)
+ "\
+Same as `string-match' except this function does not change the match data."
+ (save-match-data
+ (string-match regexp string start))))
+
+(if (fboundp 'string-prefix-p)
+ (defalias 'gnus-string-prefix-p 'string-prefix-p)
+ (defun gnus-string-prefix-p (str1 str2 &optional ignore-case)
+ "Return non-nil if STR1 is a prefix of STR2.
+If IGNORE-CASE is non-nil, the comparison is done without paying attention
+to case differences."
+ (and (<= (length str1) (length str2))
+ (let ((prefix (substring str2 0 (length str1))))
+ (if ignore-case
+ (string-equal (downcase str1) (downcase prefix))
+ (string-equal str1 prefix))))))
+
+;; Simple check: can be a macro but this way, although slow, it's really clear.
+;; We don't use `bound-and-true-p' because it's not in XEmacs.
+(defun gnus-bound-and-true-p (sym)
+ (and (boundp sym) (symbol-value sym)))
+
+(if (fboundp 'timer--function)
+ (defalias 'gnus-timer--function 'timer--function)
+ (defun gnus-timer--function (timer)
+ (elt timer 5)))
+