Btukfyl

I'm struggling with hyphenation of long URLs (using command url{}).

Line breaking works fine in cases when URL is just part of line which doesn't fit to text area width. That means URL is hyphenated correctly if line starts with some text before URL - or if hyphenated URL is followed by other text which is also hyphenated.

Problem is in parts of URL which are at the line alone

1. first line of very long URL




2. middle lines of very long hyphenated URL

At screenshot there is visible that both cases overflowed the text area - case 1 is clearly visible, but also case 2 overflowed by few pixels.

In real document overflowed area is variable depending on contents which makes sometimes collisions with objects on the right side (images, ...).

How to hyphenate URLs correctly to avoid such overflows?

• ideal solution is perfectly aligned block




• but acceptable is also solution with underflowed line instead of overflowed (earlier line break instead of late)

I guess problem is mainly caused by non-proportional font and is fixed if other proportional text is present at the same line, but how to handle alone parts of long URLs?

documentclass[a4paper]{book}



usepackage{fontspec}



usepackage{polyglossia}

setmainlanguage{czech}



usepackage{ulem}

usepackage[unicode]{hyperref}

defUrlBreaks{do{a}} % Force correct hyphenation for this example





usepackage{pdfpages}



usepackage{needspace}



begin{document}



Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text.newline

url{http://aaa.bbb.ccc/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}newline

Some text before. url{http://aaa.bbb.ccc/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after.



end{document}

Shorter MWE

documentclass[a4paper]{book}



usepackage{hyperref}

defUrlBreaks{do{a}}



begin{document}

Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text.newline

url{http://aaa.bbb.ccc/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}newline

Some text before. url{http://aaa.bbb.ccc/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after.

end{document}

url's are not hyphenated. They are broken. As they are actually set in math the parts are blocks of quite fix width, this makes it sometimes difficult to fill up a line.
You can add a bit stretchability after the a to avoid the problem:

documentclass[a4paper]{book}



usepackage{fontspec}



usepackage{polyglossia}

setmainlanguage{czech}



usepackage{ulem}

usepackage[unicode]{hyperref}

%defUrlBreaks{do{a}} %

% some stretchability:

defdo#1{apptoUrlSpecials{do#1{mathchar`#1 mskip 0mu plus 1mupenalty100}}}%

 doa



begin{document}



Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text.newline

url{http://aaa.bbb.ccc/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}newline

Some text before. url{http://aaa.bbb.ccc/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after.



end{document} 

You can use the xurl package:

documentclass[a4paper]{book}



usepackage{fontspec}



usepackage{polyglossia}

setmainlanguage{czech}

usepackage{showframe}

renewcommand{ShowFrameLinethickness}{0.3pt}

usepackage{ulem}

usepackage{xurl}

usepackage[unicode]{hyperref}



usepackage{pdfpages}



usepackage{needspace}



begin{document}



Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text. Reference text.newline

url{http://aaa.bbb.ccc/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}newline

Some text before. url{http://abc.bbb.ccc/abcabcaaaaaaabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabca} Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after.



end{document} 

Just add the call of package xurl before package hyperref.

The following MWE

documentclass[a4paper]{book}



usepackage{fontspec}



usepackage{polyglossia}

setmainlanguage{czech}



usepackage{ulem}

usepackage[hyphens]{xurl} % <==========================================

usepackage[unicode]{hyperref}



usepackage{pdfpages}



usepackage{needspace}





begin{document}



Reference text. Reference text. Reference text. Reference text. 

Reference text. Reference text. Reference text. Reference text. 

Reference text. Reference text.newline

url{http://aaa.bbb.ccc/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}newline

Some text before. url{http://aaa.bbb.ccc/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after.



end{document}

gives you:

I will inform the maintainer of xurl about this bug. Meanwhile you can use the following (not perfect, but better than nothing ...) code ( I corrected the code in def: defUrlBreaks{doa}):

documentclass[a4paper]{book}



usepackage{fontspec}



usepackage{polyglossia}

setmainlanguage{czech}



usepackage{pdfpages}

usepackage{needspace}

usepackage{ulem}

usepackage{showframe}



%usepackage{xurl} % <==========================================

usepackage[unicode]{hyperref}

defUrlBreaks{doa}





begin{document}



Reference text. Reference text. Reference text. Reference text. 

Reference text. Reference text. Reference text. Reference text. 

Reference text. Reference text.



url{http://aaa.bbb.ccc/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}



Some text before. url{http://aaa.bbb.ccc/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa} Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after. Some text after.



end{document}

with the result: