- (or (catch 'tag
- (let ((rest charsets-mime-charset-alist)
- cell)
- (while (setq cell (car rest))
- (if (catch 'not-subset
- (let ((set1 charsets)
- (set2 (car cell))
- obj)
- (while set1
- (setq obj (car set1))
- (or (memq obj set2)
- (throw 'not-subset nil))
- (setq set1 (cdr set1)))
- t))
- (throw 'tag (cdr cell)))
- (setq rest (cdr rest)))))
- default-mime-charset)))
+ (catch 'tag
+ (let ((rest charsets-mime-charset-alist)
+ cell)
+ (while (setq cell (car rest))
+ (if (catch 'not-subset
+ (let ((set1 charsets)
+ (set2 (car cell))
+ obj)
+ (while set1
+ (setq obj (car set1))
+ (or (memq obj set2)
+ (throw 'not-subset nil))
+ (setq set1 (cdr set1)))
+ t))
+ (throw 'tag (cdr cell)))
+ (setq rest (cdr rest)))
+ ))))
+
+(defun find-mime-charset-by-charsets (charsets &optional mode &rest args)
+ "Like `charsets-to-mime-charset', but it does not return nil.
+
+When suitable mime-charset is not found and variable
+`default-mime-charset-detect-method-for-write' is not nil,
+`find-mime-charset-by-charsets' calls the variable as function and
+return the return value of the function.
+Interface of the function is (MODE CHARSETS &rest ARGS).
+
+When suitable mime-charset is not found and variable
+`default-mime-charset-detect-method-for-write' is nil,
+variable `default-mime-charset-for-write' is returned."
+ (or (charsets-to-mime-charset charsets)
+ (if default-mime-charset-detect-method-for-write
+ (apply default-mime-charset-detect-method-for-write
+ mode charsets args)
+ default-mime-charset-for-write)))