Optional 4th argument STRING, if non-nil, is a string containing text
to compose.
-The return value is number of composed characters."
- (if (< (1+ from) to)
- (prog1 (- to from)
- (if string
- (compose-string string from to)
- (compose-region from to))
- (- to from))))
+The return value is the number of composed characters."
+ (when (< (1+ from) to)
+ (if string
+ (compose-string string from to)
+ (compose-region from to))
+ (- to from)))
;; Register a function to compose Unicode diacrtics and marks.
(let ((patterns '(("\\C^\\c^+" . diacritic-composition-function))))