(svn r9011) -Codechange (r9003): Rework Utf8PrevChar so that it returns a pointer to the previous UTF8 character's first byte instead of a byte-length offset

src/string.h

@@ -107,25 +107,17 @@ static inline bool IsUtf8Part(char c)
 }
 
 /**
- * Retrieve the (partial) length of the previous UNICODE character
- * in an UTF-8 encoded string.
- * @param s char pointer pointing to the first char of the next character
- * @returns the decoded length in bytes (size) of the UNICODE character
- * that was just before the one where 's' is pointing to
- * @note If 's' is not pointing to the first byte of the next UNICODE character
- * only a partial length of the sequence will be returned.
- * For example given this sequence: 0xE3 0x85 0x80, 0xE3 0x81 0x9E
- * 1. 's' is pointing to the second 0xE3, return value is 3
- * 2. 's' is pointing to 0x80, return value is 2.
- * So take care with the return values of this function. To get the real length
- * for an (invalid) sequence, pass the string offset of this function's return
- * value to Utf8EncodedCharLen() or Utf8Decode()
+ * Retrieve the previous UNICODE character in an UTF-8 encoded string.
+ * @param s char pointer pointing to (the first char of) the next character
+ * @returns a pointer in 's' to the previous UNICODE character's first byte
+ * @note The function should not be used to determine the length of the previous
+ * encoded char because it might be an invalid/corrupt start-sequence
  */
-static inline size_t Utf8PrevCharLen(const char *s)
+static inline char *Utf8PrevChar(const char *s)
 {
-	size_t len = 1;
-	while (IsUtf8Part(*--s)) len++;
-	return len;
+	const char *ret = s;
+	while (IsUtf8Part(*--ret));
+	return (char*)ret;
 }