qt: fonts: allow SubstituteFonts to filter based on user's language

SubstituteFonts() has been moved to after app identification so that QSettings
are accessible.

src/qt/bitcoin.cpp

@@ -89,10 +89,24 @@ static std::string Translate(const char* psz)
     return QCoreApplication::translate("bitcoin-core", psz).toStdString();
 }
 
+static QString GetLangTerritory()
+{
+    QSettings settings;
+    // Get desired locale (e.g. "de_DE")
+    // 1) System default language
+    QString lang_territory = QLocale::system().name();
+    // 2) Language from QSettings
+    QString lang_territory_qsettings = settings.value("language", "").toString();
+    if(!lang_territory_qsettings.isEmpty())
+        lang_territory = lang_territory_qsettings;
+    // 3) -lang command line argument
+    lang_territory = QString::fromStdString(GetArg("-lang", lang_territory.toStdString()));
+    return lang_territory;
+}
+
 /** Set up translations */
 static void initTranslations(QTranslator &qtTranslatorBase, QTranslator &qtTranslator, QTranslator &translatorBase, QTranslator &translator)
 {
-    QSettings settings;
 
     // Remove old translators
     QApplication::removeTranslator(&qtTranslatorBase);
@@ -102,13 +116,7 @@ static void initTranslations(QTranslator &qtTranslatorBase, QTranslator &qtTrans
 
     // Get desired locale (e.g. "de_DE")
     // 1) System default language
-    QString lang_territory = QLocale::system().name();
+    QString lang_territory = GetLangTerritory();
-    // 2) Language from QSettings
-    QString lang_territory_qsettings = settings.value("language", "").toString();
-    if(!lang_territory_qsettings.isEmpty())
-        lang_territory = lang_territory_qsettings;
-    // 3) -lang command line argument
-    lang_territory = QString::fromStdString(GetArg("-lang", lang_territory.toStdString()));
 
     // Convert to "de" only by truncating "_DE"
     QString lang = lang_territory;
@@ -498,8 +506,6 @@ int main(int argc, char *argv[])
     Q_INIT_RESOURCE(bitcoin);
     Q_INIT_RESOURCE(bitcoin_locale);
 
-    GUIUtil::SubstituteFonts();
-
     BitcoinApplication app(argc, argv);
 #if QT_VERSION > 0x050100
     // Generate high-dpi pixmaps
@@ -521,6 +527,7 @@ int main(int argc, char *argv[])
     QApplication::setOrganizationName(QAPP_ORG_NAME);
     QApplication::setOrganizationDomain(QAPP_ORG_DOMAIN);
     QApplication::setApplicationName(QAPP_APP_NAME_DEFAULT);
+    GUIUtil::SubstituteFonts(GetLangTerritory());
 
     /// 4. Initialization of translations, so that intro dialog is in user's language
     // Now that QSettings are accessible, initialize translations

src/qt/guiutil.cpp

@@ -383,7 +383,7 @@ void openDebugLogfile()
         QDesktopServices::openUrl(QUrl::fromLocalFile(boostPathToQString(pathDebug)));
 }
 
-void SubstituteFonts()
+void SubstituteFonts(const QString& language)
 {
 #if defined(Q_OS_MAC)
 // Background:

src/qt/guiutil.h

@@ -107,7 +107,7 @@ namespace GUIUtil
     void openDebugLogfile();
 
     // Replace invalid default fonts with known good ones
-    void SubstituteFonts();
+    void SubstituteFonts(const QString& language);
 
     /** Qt event filter that intercepts ToolTipChange events, and replaces the tooltip with a rich text
       representation if needed. This assures that Qt can word-wrap long tooltip messages.