My dialogue code is not working as it should!

[TodNaz via Digitalmars-d-learn]

Hello! I can’t understand ... My dialogue code is not working as 
it should! He must, if the texture does not exceed the maximum 
value, add a character, otherwise go to a new line until the text 
ends. But he constantly makes the transition to a new line. 
Either I'm stupid, or something is wrong. If something is not 
clear, knock! Preferably by mail: tod....@ya.ru

Code:
https://pastebin.com/tDtUnjYu