-(eval-and-compile
- (if (fboundp 'macroexpand-all)
- (defalias 'gnus-macroexpand-all 'macroexpand-all)
- (defun gnus-macroexpand-all (form &optional environment)
- "Return result of expanding macros at all levels in FORM.
-If no macros are expanded, FORM is returned unchanged.
-The second optional arg ENVIRONMENT specifies an environment of macro
-definitions to shadow the loaded ones for use in file byte-compilation."
- (if (consp form)
- (let ((idx 1)
- (len (length (setq form (copy-sequence form))))
- expanded)
- (while (< idx len)
- (setcar (nthcdr idx form) (gnus-macroexpand-all (nth idx form)
- environment))
- (setq idx (1+ idx)))
- (if (eq (setq expanded (macroexpand form environment)) form)
- form
- (gnus-macroexpand-all expanded environment)))
- form))))
+(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))))))