Polyglossia multi-language - wrong fonts used?

Question

I'm trying to set up a document with Polyglossia/XeLaTeX, which should be mostly in Hebrew, with some English excerpts. However, I can't get fontspec to use the correct English font for anything other than the main (roman) font - it instead uses the Hebrew-specified fonts.

Here is my minimal example file:

\documentclass{article}
\usepackage{fontspec}
\usepackage[a4paper]{geometry}

\makeatletter

\setmainfont[Language=English,Script=Latin]{Nimbus Roman No9 L}
\setsansfont[Language=English,Script=Latin]{Nimbus Sans L}
\setmonofont[Language=English,Script=Latin]{Nimbus Mono L}
\newfontfamily\hebrewfont[Language=Hebrew,Script=Hebrew,Scale=3.0]{Frank Ruehl CLM}
\newfontfamily\hebrewfontsf[Language=Hebrew,Script=Hebrew,Scale=3.0]{Nachlieli CLM}
\newfontfamily\hebrewfonttt[Language=Hebrew,Script=Hebrew,Scale=3.0]{Miriam Mono CLM}
\makeatother

\usepackage{xunicode}
\usepackage{polyglossia}
\setdefaultlanguage{hebrew}
\setotherlanguage{english}
\begin{document}
בדיקה, באיזה פונט זה יוצג \textenglish{\ttfamily{Hello, World!}}.


\begin{english}
Hello, \sffamily{Sans}, \ttfamily{Mono}
\end{english}

\end{document}

Hebrew fonts scale to better see outcome. The result looks like this:

As you can see, only the default (roman) English font is used, while all other English text uses the scaled (Hebrew) fonts. I have tried with or without Language/Script specifications, but results are always the same.

Edit: Changing it so English is default and Hebrew is other seems to fix it, but this is far from ideal - the document would be 95% Hebrew at least. But maybe it hints towards the root cause?

Edit2: Changing default language to English also has the undesired outcome of making it so Hebrew Sans-Serif and Typewriter/Mono text disappears completely.

Edit3: The proposed fix in Ulrike Fischer's answer has the side effect of making it so after the first use of \textenglish, all section titles are wrongly rendered using the English fonts:

\documentclass{article}
\usepackage{fontspec}
\usepackage[a4paper]{geometry}
\usepackage{xunicode}
\usepackage{polyglossia}

\setmainfont{DejaVu Sans}
\setsansfont{DejaVu Sans}
\setmonofont{DejaVu Sans}
\newfontfamily\englishfont{TeX Gyre Termes}
\newfontfamily\englishfontsf{TeX Gyre Heros}
\newfontfamily\englishfonttt{TeX Gyre Cursor}

\setdefaultlanguage{hebrew}
\setotherlanguage{english}

\makeatletter 
\addto\inlineextras@english{\xpg@set@normalfont{english}}
\addto\blockextras@english{\xpg@set@normalfont{english}}
\makeatother


\begin{document}
\section{חלק ראשון}
נכתוב באנגלית \textenglish{Hello, World!}
ומעכשיו כל הכותרות לא יופיעו
\section{חלק שני}
הכותרת לא מופיעה, אבל הטקסט כן.

\end{document}

Which results in:

Different fonts will have different behaviors - the previously used Nimbus fonts only show spaces, while the Liberation ones show empty squares - I guess it has to do with what those fonts have in the Hebrew glyph locations.

Answer 1

hebrew is your main language and so it would feel like a hack to set english to the default language only to get the fonts right.

Imho there is a bug in polyglossia, it doesn't seem to reset the fonts correctly.

The following seems to work to correct the problem. As I don't have your fonts I had to change them.

Edit

As noted in the comment my first solution broke the fonts in \section (and other places). The reason is that \xpg@set@normalfont redefines \normalfont globally. The following correct this, but it could have other side effects. Also it is more a work-around than a solution.

On the whole I think that the font changing commands in polyglossia are not symmetric. There is code for the case "latin=main, hebrew=other" but not the other way round.

\documentclass{article}
\usepackage[a4paper]{geometry}    
\usepackage{polyglossia}

\setmainfont{DejaVu Sans}
\setsansfont{DejaVu Sans}
\setmonofont{DejaVu Sans}
\newfontfamily\englishfont{TeX Gyre Termes}
\newfontfamily\englishfontsf{TeX Gyre Heros}
\newfontfamily\englishfonttt{TeX Gyre Cursor}

\setdefaultlanguage{hebrew}
\setotherlanguage{english}

\makeatletter
\def\xpg@set@normalfont#1{%
  \letcs{\rmfamily}{#1@font@rm}%
  \letcs{\sffamily}{#1@font@sf}%
  \letcs{\ttfamily}{#1@font@tt}%
  \def\normalfont{\protect\xpg@select@fontfamily{#1}}%def instead of gdef
  \gdef\reset@font{\protect\normalfont}%
}
\addto\inlineextras@english{\xpg@set@normalfont{english}}
\addto\blockextras@english{\xpg@set@normalfont{english}}
\makeatother



\begin{document}
\section{חלק ראשון}
נכתוב באנגלית \textenglish{Hello, World!}
ומעכשיו כל הכותרות לא יופיעו

\begin{english}
blub \sffamily blub \ttfamily blb
\end{english}


\section{חלק שני}
הכותרת לא מופיעה, אבל הטקסט כן.

\end{document}

Answer 2

Apparently \sffamilylatin and \ttfamilylatin will help a lot if the main language is non-Latin (page 6 of polyglossia documentation). We can then conditionally re-define \sffamily and \ttfamily to use these latin versions by checking if the active language is English, with \IfLanguageName{english}{true part}{false part}.

(I had previous used \iflanguage, but later found out that its use is discouraged, and \IfLanguageName from the iflang package is preferred.)

\documentclass[12pt]{article}
\usepackage{polyglossia}
\usepackage{iflang}
\setdefaultlanguage{hebrew}
\setotherlanguage{english}

% I don't actually which Hebrew fonts counts as serif or sans serif...
\newfontfamily\hebrewfont[Language=Hebrew,Script=Hebrew]{David CLM}
\newfontfamily\hebrewfontsf[Language=Hebrew,Script=Hebrew]{Miriam CLM}
\newfontfamily\hebrewfonttt[Language=Hebrew,Script=Hebrew]{Miriam Mono CLM}
\newfontfamily\englishfont{FreeSerif}
\newfontfamily\sffamilylatin{FreeSans}
\newfontfamily\ttfamilylatin{FreeMono}

% Conditionally redefine \sffamily, \ttfamily to use
% \sffamilylatin, \ttfamilylatin if active language is english
\AtBeginDocument{
  \let\oldttfamily\ttfamily
  \let\oldsffamily\sffamily
  \renewcommand{\ttfamily}{\IfLanguageName{english}{\ttfamilylatin}{\oldttfamily}}
  \renewcommand{\sffamily}{\IfLanguageName{english}{\sffamilylatin}{\oldsffamily}}
}

\begin{document}
בדיקה, באיזה פונט זה יוצג
\textsf{בדיקה, באיזה פונט זה יוצג}

\section{חלק ראשון}

נכתוב באנגלית \textenglish{Hello, World!}
ומעכשיו כל הכותרות לא יופיעו

\begin{english}
blub \sffamily blub \ttfamily blub \textsf{blub} \texttt{blub}
\end{english}


\section{חלק שני}
הכותרת לא מופיעה, אבל הטקסט כן.
\end{document}

Example project: https://www.overleaf.com/5971027jytqjd#/19831055/