static int adjustEnd(String msg, int start, int originEnd) {
    if (originEnd == msg.length()) {
      // Already end of message.
      return originEnd;
    }
    if (msg.charAt(originEnd) == '\n') {
      // Already prior to '\n'.
      return originEnd;
    }
    // Search back for '\n'.
    int last = originEnd - 1;
    while (start < last) {
      if (msg.charAt(last) == '\n') {
        return last;
      }
      last--;
    }
    return originEnd;
  }
Move the end to the nearest line separator('\n') (if exist).
xlog/src/main/java/com/elvishew/xlog/printer/AndroidPrinter.java