From 3335344261baf578872441242affd5375d9e4019 Mon Sep 17 00:00:00 2001
From: Juergen Spitzmueller <spitz@lyx.org>
Date: Thu, 9 Jul 2020 11:39:43 +0200
Subject: [PATCH] Provide option to prevent unnecessary font loading.

If an OSF font is an alternative to a non-OSF one, only load the OSFFont
if osf is requested.
---
 lib/latexfonts     |  6 ++++++
 src/LaTeXFonts.cpp | 32 ++++++++++++++++++++------------
 src/LaTeXFonts.h   |  9 +++++++--
 3 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/lib/latexfonts b/lib/latexfonts
index 784ed3378f..eaf9e4c317 100644
--- a/lib/latexfonts
+++ b/lib/latexfonts
@@ -19,6 +19,7 @@
 #	OsfOption          <option for oldstyle figure support>
 #	OsfFont            <extra font for oldstyle figures>
 #	OsfDefault         <0|1>
+#	OsfFontOnly        <0|1>
 #	ScOption           <option for true smallcaps support>
 #	OsfScOption        <option for combined osf and true smallcaps support>
 #	ScaleOption        <option for font scaling>
@@ -65,6 +66,9 @@
 #   tags.
 # * OsfFont is a font that is loaded additionally in and that provides
 #   Old Style Figures for a given font (e.g. eco).
+# * If OsfFontOnly is true, then the OsfFont will replace the non-OsF
+#   one (only OsfFont is loaded if osf is true). Otherwise it will
+#   complement the non-osf font.
 # * OsfScOption overrides any OsfOption and ScOption if both features
 #   are selected.
 # * ScOption and OsfScOption are currently only supported for rm fonts.
@@ -500,6 +504,7 @@ AltFont ppl
 	GuiName          "Palatino"
 	Family           rm
 	OsfFont          pplj
+	OsfFontOnly      1
 	SwitchDefault    1
 EndFont
 
@@ -600,6 +605,7 @@ AltFont futs
 	Family           rm
 	SwitchDefault    1
 	OsfFont          futj
+	OsfFontOnly      1
 EndFont
 
 AltFont futj
diff --git a/src/LaTeXFonts.cpp b/src/LaTeXFonts.cpp
index 12c0856c5d..e58b55f504 100644
--- a/src/LaTeXFonts.cpp
+++ b/src/LaTeXFonts.cpp
@@ -68,7 +68,7 @@ bool LaTeXFont::available(bool ot1, bool nomath)
 
 bool LaTeXFont::providesNoMath(bool ot1, bool complete)
 {
-	docstring const usedfont = getUsedFont(ot1, complete, false);
+	docstring const usedfont = getUsedFont(ot1, complete, false, false);
 
 	if (usedfont.empty())
 		return false;
@@ -81,7 +81,7 @@ bool LaTeXFont::providesNoMath(bool ot1, bool complete)
 
 bool LaTeXFont::providesOSF(bool ot1, bool complete, bool nomath)
 {
-	docstring const usedfont = getUsedFont(ot1, complete, nomath);
+	docstring const usedfont = getUsedFont(ot1, complete, nomath, false);
 
 	if (usedfont.empty())
 		return false;
@@ -98,7 +98,7 @@ bool LaTeXFont::providesOSF(bool ot1, bool complete, bool nomath)
 
 bool LaTeXFont::providesSC(bool ot1, bool complete, bool nomath)
 {
-	docstring const usedfont = getUsedFont(ot1, complete, nomath);
+	docstring const usedfont = getUsedFont(ot1, complete, nomath, false);
 
 	if (usedfont.empty())
 		return false;
@@ -113,7 +113,7 @@ bool LaTeXFont::providesSC(bool ot1, bool complete, bool nomath)
 
 bool LaTeXFont::hasMonolithicExpertSet(bool ot1, bool complete, bool nomath)
 {
-	docstring const usedfont = getUsedFont(ot1, complete, nomath);
+	docstring const usedfont = getUsedFont(ot1, complete, nomath, false);
 
 	if (usedfont.empty())
 		return false;
@@ -126,7 +126,7 @@ bool LaTeXFont::hasMonolithicExpertSet(bool ot1, bool complete, bool nomath)
 
 bool LaTeXFont::providesScale(bool ot1, bool complete, bool nomath)
 {
-	docstring const usedfont = getUsedFont(ot1, complete, nomath);
+	docstring const usedfont = getUsedFont(ot1, complete, nomath, false);
 
 	if (usedfont.empty())
 		return false;
@@ -140,7 +140,7 @@ bool LaTeXFont::providesScale(bool ot1, bool complete, bool nomath)
 
 bool LaTeXFont::providesMoreOptions(bool ot1, bool complete, bool nomath)
 {
-	docstring const usedfont = getUsedFont(ot1, complete, nomath);
+	docstring const usedfont = getUsedFont(ot1, complete, nomath, false);
 
 	if (usedfont.empty())
 		return false;
@@ -154,7 +154,7 @@ bool LaTeXFont::providesMoreOptions(bool ot1, bool complete, bool nomath)
 
 bool LaTeXFont::provides(std::string const & name, bool ot1, bool complete, bool nomath)
 {
-	docstring const usedfont = getUsedFont(ot1, complete, nomath);
+	docstring const usedfont = getUsedFont(ot1, complete, nomath, false);
 
 	if (usedfont.empty())
 		return false;
@@ -171,9 +171,11 @@ bool LaTeXFont::provides(std::string const & name, bool ot1, bool complete, bool
 }
 
 
-docstring const LaTeXFont::getUsedFont(bool ot1, bool complete, bool nomath)
+docstring const LaTeXFont::getUsedFont(bool ot1, bool complete, bool nomath, bool osf)
 {
-	if (nomath && !nomathfont_.empty() && available(ot1, true))
+	if (osf && osfFontOnly())
+		return osffont_;
+	else if (nomath && !nomathfont_.empty() && available(ot1, true))
 		return nomathfont_;
 	else if (ot1 && !ot1font_.empty())
 		return (ot1font_ == "none") ? docstring() : ot1font_;
@@ -201,7 +203,7 @@ docstring const LaTeXFont::getUsedFont(bool ot1, bool complete, bool nomath)
 		for (size_t i = 0; i < altfonts_.size(); ++i) {
 			LaTeXFont altf = altFont(altfonts_[i]);
 			if (altf.available(ot1, nomath))
-				return altf.getUsedFont(ot1, complete, nomath);
+				return altf.getUsedFont(ot1, complete, nomath, osf);
 		}
 	}
 
@@ -211,7 +213,7 @@ docstring const LaTeXFont::getUsedFont(bool ot1, bool complete, bool nomath)
 
 docstring const LaTeXFont::getUsedPackage(bool ot1, bool complete, bool nomath)
 {
-	docstring const usedfont = getUsedFont(ot1, complete, nomath);
+	docstring const usedfont = getUsedFont(ot1, complete, nomath, false);
 	if (usedfont.empty())
 		return docstring();
 	return theLaTeXFonts().getLaTeXFont(usedfont).package();
@@ -295,7 +297,7 @@ string const LaTeXFont::getLaTeXCode(bool dryrun, bool ot1, bool complete, bool
 {
 	ostringstream os;
 
-	docstring const usedfont = getUsedFont(ot1, complete, nomath);
+	docstring const usedfont = getUsedFont(ot1, complete, nomath, osf);
 	if (usedfont.empty())
 		return string();
 	else if (usedfont != name_)
@@ -357,6 +359,7 @@ bool LaTeXFont::readFont(Lexer & lex)
 		LF_NOMATHFONT,
 		LF_OSFDEFAULT,
 		LF_OSFFONT,
+		LF_OSFFONTONLY,
 		LF_OSFOPTION,
 		LF_OSFSCOPTION,
 		LF_OT1_FONT,
@@ -383,6 +386,7 @@ bool LaTeXFont::readFont(Lexer & lex)
 		{ "nomathfont",           LF_NOMATHFONT },
 		{ "osfdefault",           LF_OSFDEFAULT },
 		{ "osffont",              LF_OSFFONT },
+		{ "osffontonly",          LF_OSFFONTONLY },
 		{ "osfoption",            LF_OSFOPTION },
 		{ "osfscoption",          LF_OSFSCOPTION },
 		{ "ot1font",              LF_OT1_FONT },
@@ -452,6 +456,9 @@ bool LaTeXFont::readFont(Lexer & lex)
 		case LF_OSFDEFAULT:
 			lex >> osfdefault_;
 			break;
+		case LF_OSFFONTONLY:
+			lex >> osffontonly_;
+			break;
 		case LF_OSFSCOPTION:
 			lex >> osfscoption_;
 			break;
@@ -504,6 +511,7 @@ bool LaTeXFont::read(Lexer & lex)
 	switchdefault_ = 0;
 	osfdefault_ = 0;
 	moreopts_ = 0;
+	osffontonly_ = 0;
 
 	if (!lex.next()) {
 		lex.printError("No name given for LaTeX font: `$$Token'.");
diff --git a/src/LaTeXFonts.h b/src/LaTeXFonts.h
index 79bd34b7ec..a6d875dd60 100644
--- a/src/LaTeXFonts.h
+++ b/src/LaTeXFonts.h
@@ -27,7 +27,8 @@ class LaTeXFont {
 public:
 	/// TeX font
 	// FIXME Add fontenc tag to classes which is used if no font is specified?
-	LaTeXFont() : osfdefault_(false), switchdefault_(false), moreopts_(false) { fontenc_.push_back("T1"); }
+	LaTeXFont() : osfdefault_(false), switchdefault_(false), moreopts_(false),
+		osffontonly_(false) { fontenc_.push_back("T1"); }
 	/// The font name
 	docstring const & name() { return name_; }
 	/// The name to appear in the document dialog
@@ -67,6 +68,8 @@ public:
 	bool switchdefault() const { return switchdefault_; }
 	/// Does the font provide Old Style Figures as default?
 	bool osfDefault() const { return osfdefault_; }
+	/// Does OSF font replace (rather than complement) the non-OSF one?
+	bool osfFontOnly() const { return osffontonly_; }
 	/// Is this font available?
 	bool available(bool ot1, bool nomath);
 	/// Does this font provide an alternative without math?
@@ -87,7 +90,7 @@ public:
 				       std::string const & extraopts = std::string(),
 				       int const & scale = 100);
 	/// Return the actually used font
-	docstring const getUsedFont(bool ot1, bool complete, bool nomath);
+	docstring const getUsedFont(bool ot1, bool complete, bool nomath, bool osf);
 	/// Return the actually used package
 	docstring const getUsedPackage(bool ot1, bool complete, bool nomath);
 	///
@@ -149,6 +152,8 @@ private:
 	bool switchdefault_;
 	///
 	bool moreopts_;
+	///
+	bool osffontonly_;
 };