[emirmrkaljevic]

Fixes #16190

When no active break can take the next word, restart_active_breaks chose between breaking early and breaking late by comparing how short or how long the line would get. Breaking late always overflows WIDTH there, so it now always breaks before the word (unless the line is fresh, where the word has to stay). This matches GNU fmt, where WIDTH is a hard maximum.

$ printf '    at a narrow width x y\n' | fmt -w 20
    at a narrow
    width x y

Added test_fmt_width_is_a_hard_maximum. Found with behave.

[cakebaker]

Thanks!