I noticed that if I've got something like this:

```
one::two::three::four one::two::three::four one::two::three::four

```

something weird happen:

```
%                      the right page margin would be here |
%                                                          |
%                                                          v
one::two::three::four one::two::three::four one::two::three::four

```

the page margin is where I marked, but the line doesn't get broken, `::four` goes out of the page, although it is aligned so that the first colon is exactly after the margin, like if it had to be splitted.

Why doesn't the line gets broken between `one::two::three` and `::four`?  

And then why does it get aligned that way, so that `::four` goes out of the page?