Better support for (Lua|Xe)TeX files in tex2lyx

When one of the packages specific to these engines are used in the TeX file:
* set default encoding to utf-8
* set \use_non_tex_fonts to true

This is a hand-made backport of svn commit r40765.

src/tex2lyx/Preamble.cpp

@@ -401,6 +401,7 @@ Preamble::Preamble() : one_language(true)
 	h_font_sans               = "default";
 	h_font_typewriter         = "default";
 	h_font_default_family     = "default";
+	h_use_non_tex_fonts       = "false";
 	h_font_sc                 = "false";
 	h_font_osf                = "false";
 	h_font_sf_scale           = "100";
@@ -581,8 +582,12 @@ void Preamble::handle_package(Parser &p, string const & name,
 	add_package(name, options);
 	string scale;
 
-	if (is_known(name, known_xetex_packages))
+	if (is_known(name, known_xetex_packages)) {
 		xetex = true;
+		h_use_non_tex_fonts = "true";
+		if (h_inputencoding == "auto")
+			p.setEncoding("utf8");
+	}
 
 	// roman fonts
 	if (is_known(name, known_roman_fonts)) {
@@ -903,6 +908,7 @@ bool Preamble::writeLyXHeader(ostream & os, bool subdoc)
 	   << "\\font_sans " << h_font_sans << "\n"
 	   << "\\font_typewriter " << h_font_typewriter << "\n"
 	   << "\\font_default_family " << h_font_default_family << "\n"
+	   << "\\use_non_tex_fonts " << h_use_non_tex_fonts << "\n"
 	   << "\\font_sc " << h_font_sc << "\n"
 	   << "\\font_osf " << h_font_osf << "\n"
 	   << "\\font_sf_scale " << h_font_sf_scale << "\n"

src/tex2lyx/Preamble.h

@@ -90,6 +90,7 @@ private:
 	std::string h_font_sans;
 	std::string h_font_typewriter;
 	std::string h_font_default_family;
+	std::string h_use_non_tex_fonts;
 	std::string h_font_sc;
 	std::string h_font_osf;
 	std::string h_font_sf_scale;

status.20x

@@ -30,6 +30,8 @@ What's new
 * TEX2LYX IMPROVEMENTS
 
 - Support for the LaTeX-command \sindex (for split indexes).
+- Better support for XeTeX and LuaTeX documents: automatically set default
+  encoding to utf-8 and select support for non-TeX fonts.
 
 
 * USER INTERFACE