Provide option to force a local language switch where a global is not allowed (fixes #8033)

lib/doc/Customization.lyx

@@ -1,5 +1,5 @@
 #LyX 2.1 created this file. For more info see http://www.lyx.org/
-\lyxformat 446
+\lyxformat 448
 \begin_document
 \begin_header
 \textclass scrbook
@@ -140,6 +140,7 @@ End
 \author -712698321 "Jürgen Spitzmüller" 
 \author -195340706 "Georg Baum" 
 \author 5863208 "ab" 
+\author 155139281 "Jrgen Spitzmller" 
 \author 1082167584 "Kayvan Sylvan" kayvan@sylvan.com
 \author 1414654397 "Richard Heck" 
 \author 2090807402 "usti" 
@@ -15960,6 +15961,81 @@ LabelFont
 \end_inset
 
  later if you want them to be different.
+\change_inserted 155139281 1354130923
+
+\end_layout
+
+\begin_layout Description
+
+\change_inserted 155139281 1354130923
+\begin_inset Flex Code
+status collapsed
+
+\begin_layout Plain Layout
+
+\change_inserted 155139281 1354130923
+ForceLocalFontSwitch
+\end_layout
+
+\end_inset
+
+ [
+\begin_inset Flex Code
+status collapsed
+
+\begin_layout Plain Layout
+
+\change_inserted 155139281 1354130923
+
+\emph on
+0
+\end_layout
+
+\end_inset
+
+,
+\begin_inset Flex Code
+status collapsed
+
+\begin_layout Plain Layout
+
+\change_inserted 155139281 1354130923
+1
+\end_layout
+
+\end_inset
+
+] When using babel, always use a local font switch (
+\begin_inset Flex Code
+status collapsed
+
+\begin_layout Plain Layout
+
+\change_inserted 155139281 1354130923
+
+\backslash
+foreignlanguage
+\end_layout
+
+\end_inset
+
+), never a global one (such as 
+\begin_inset Flex Code
+status collapsed
+
+\begin_layout Plain Layout
+
+\change_inserted 155139281 1354130923
+
+\backslash
+selectlanguage
+\end_layout
+
+\end_inset
+
+).
+\change_unchanged
+
 \end_layout
 
 \begin_layout Description
@@ -16670,7 +16746,7 @@ string
 \end_inset
 
 ] A string that is put at the beginning of the layout content.
-\change_unchanged
+\change_inserted 155139281 1354130509
 
 \end_layout
 

lib/layouts/stdinsets.inc

@@ -406,6 +406,7 @@ InsetLayout Argument
 	  Size                Small
 	EndFont
 	MultiPar              false
+	ForceLocalFontSwitch  1
 End
 
 InsetLayout Info

src/insets/InsetLayout.cpp

@@ -41,7 +41,7 @@ InsetLayout::InsetLayout() :
 	passthru_(false), parbreakisnewline_(false), freespacing_(false), 
 	keepempty_(false), forceltr_(false), 
 	needprotect_(false), intoc_(false), spellcheck_(true), 
-	resetsfont_(true), display_(true)
+	resetsfont_(true), display_(true), forcelocalfontswitch_(false)
 { 
 	labelfont_.setColor(Color_error);
 }
@@ -87,6 +87,7 @@ bool InsetLayout::read(Lexer & lex, TextClass const & tclass)
 		IL_DECORATION,
 		IL_DISPLAY,
 		IL_FONT,
+		IL_FORCE_LOCAL_FONT_SWITCH,
 		IL_FORCELTR,
 		IL_FORCEPLAIN,
 		IL_FREESPACING,
@@ -135,6 +136,7 @@ bool InsetLayout::read(Lexer & lex, TextClass const & tclass)
 		{ "display", IL_DISPLAY },
 		{ "end", IL_END },
 		{ "font", IL_FONT },
+		{ "forcelocalfontswitch", IL_FORCE_LOCAL_FONT_SWITCH },
 		{ "forceltr", IL_FORCELTR },
 		{ "forceplain", IL_FORCEPLAIN },
 		{ "freespacing", IL_FREESPACING },
@@ -236,6 +238,9 @@ bool InsetLayout::read(Lexer & lex, TextClass const & tclass)
 		case IL_LEFTDELIM:
 			lex >> leftdelim_;
 			break;
+		case IL_FORCE_LOCAL_FONT_SWITCH:
+			lex >> forcelocalfontswitch_;
+			break;
 		case IL_RIGHTDELIM:
 			lex >> rightdelim_;
 			break;

src/insets/InsetLayout.h

@@ -162,6 +162,8 @@ public:
 	bool resetsFont() const { return resetsfont_; }
 	///
 	bool isDisplay() const { return display_; }
+	///
+	bool forcelocalfontswitch() const { return forcelocalfontswitch_; }
 private:
 	///
 	void makeDefaultCSS() const;
@@ -263,6 +265,8 @@ private:
 	///
 	bool display_;
 	///
+	bool forcelocalfontswitch_;
+	///
 	Layout::LaTeXArgMap latexargs_;
 };
 

src/output_latex.cpp

@@ -551,10 +551,21 @@ void TeXOnePar(Buffer const & buf,
 		getPolyglossiaEnvName(doc_language) : doc_language->babel();
 	string const outer_lang = use_polyglossia ?
 		getPolyglossiaEnvName(outer_language) : outer_language->babel();
-	string const lang_begin_command = use_polyglossia ?
+	string lang_begin_command = use_polyglossia ?
 		"\\begin{$$lang}" : lyxrc.language_command_begin;
-	string const lang_end_command = use_polyglossia ?
+	string lang_end_command = use_polyglossia ?
 		"\\end{$$lang}" : lyxrc.language_command_end;
+	// the '%' is necessary to prevent unwanted whitespace
+	string lang_command_termination = "%\n";
+
+	// In some insets (such as Arguments), we cannot use \selectlanguage
+	bool const localswitch = !use_polyglossia
+		&& text.inset().getLayout().forcelocalfontswitch();
+	if (localswitch) {
+		lang_begin_command = lyxrc.language_command_local;
+		lang_end_command = "}";
+		lang_command_termination.clear();
+	}
 
 	if (par_lang != prev_lang
 		// check if we already put language command in TeXEnvironment()
@@ -570,8 +581,7 @@ void TeXOnePar(Buffer const & buf,
 			os << from_ascii(subst(lang_end_command,
 				"$$lang",
 				prev_lang))
-			   // the '%' is necessary to prevent unwanted whitespace
+			   << lang_command_termination;
-			   << "%\n";
 		}
 
 		// We need to open a new language if we couldn't close the previous
@@ -629,8 +639,7 @@ void TeXOnePar(Buffer const & buf,
 						os << "["
 						  << from_ascii(par_language->polyglossiaOpts())
 						  << "]";
-				   // the '%' is necessary to prevent unwanted whitespace
+				os << lang_command_termination;
-				os << "%\n";
 			}
 		}
 	}
@@ -686,8 +695,7 @@ void TeXOnePar(Buffer const & buf,
 						lang_begin_command,
 						"$$lang",
 						par_lang))
-					// the '%' is necessary to prevent unwanted whitespace
+					<< lang_command_termination;
-					<< "%\n";
 				}
 				runparams.encoding = encoding;
 			}
@@ -830,16 +838,16 @@ void TeXOnePar(Buffer const & buf,
 						lang_begin_command,
 						"$$lang",
 						current_lang));
-					pending_newline = true;
+					pending_newline = !localswitch;
-					unskip_newline = true;
+					unskip_newline = !localswitch;
 				}
 			} else if (!par_lang.empty()) {
 				os << from_ascii(subst(
 					lang_end_command,
 					"$$lang",
 					par_lang));
-				pending_newline = true;
+				pending_newline = !localswitch;
-				unskip_newline = true;
+				unskip_newline = !localswitch;
 			}
 		}
 	}