fix: Don't show unicode replacement boxes on unsupported languages.

src/widget/form/settings/generalform.cpp

@@ -7,6 +7,7 @@
 #include "ui_generalsettings.h"
 
 #include <QFileDialog>
+#include <QFontDatabase>
 #include <cmath>
 
 #include "src/core/core.h"
@@ -75,20 +76,83 @@ QStringList locales = {
     "zh_TW"
 };
 // clang-format on
+
+QFontDatabase::WritingSystem writingSystem(QLocale::Script script)
+{
+    switch (script) {
+    case QLocale::Script::AnyScript:
+        return QFontDatabase::WritingSystem::Any;
+    case QLocale::Script::ArabicScript:
+        return QFontDatabase::WritingSystem::Arabic;
+    case QLocale::Script::ArmenianScript:
+        return QFontDatabase::WritingSystem::Armenian;
+    case QLocale::Script::BengaliScript:
+        return QFontDatabase::WritingSystem::Bengali;
+    case QLocale::Script::CyrillicScript:
+        return QFontDatabase::WritingSystem::Cyrillic;
+    case QLocale::Script::DevanagariScript:
+        return QFontDatabase::WritingSystem::Devanagari;
+    case QLocale::Script::GeorgianScript:
+        return QFontDatabase::WritingSystem::Georgian;
+    case QLocale::Script::GreekScript:
+        return QFontDatabase::WritingSystem::Greek;
+    case QLocale::Script::GujaratiScript:
+        return QFontDatabase::WritingSystem::Gujarati;
+    case QLocale::Script::GurmukhiScript:
+        return QFontDatabase::WritingSystem::Gurmukhi;
+    case QLocale::Script::HebrewScript:
+        return QFontDatabase::WritingSystem::Hebrew;
+    case QLocale::Script::JapaneseScript:
+        return QFontDatabase::WritingSystem::Japanese;
+    case QLocale::Script::KannadaScript:
+        return QFontDatabase::WritingSystem::Kannada;
+    case QLocale::Script::KhmerScript:
+        return QFontDatabase::WritingSystem::Khmer;
+    case QLocale::Script::KoreanScript:
+        return QFontDatabase::WritingSystem::Korean;
+    case QLocale::Script::LaoScript:
+        return QFontDatabase::WritingSystem::Lao;
+    case QLocale::Script::LatinScript:
+        return QFontDatabase::WritingSystem::Latin;
+    case QLocale::Script::MalayalamScript:
+        return QFontDatabase::WritingSystem::Malayalam;
+    case QLocale::Script::MyanmarScript:
+        return QFontDatabase::WritingSystem::Myanmar;
+    case QLocale::Script::OriyaScript:
+        return QFontDatabase::WritingSystem::Oriya;
+    case QLocale::Script::SinhalaScript:
+        return QFontDatabase::WritingSystem::Sinhala;
+    case QLocale::Script::TamilScript:
+        return QFontDatabase::WritingSystem::Tamil;
+    case QLocale::Script::TeluguScript:
+        return QFontDatabase::WritingSystem::Telugu;
+    case QLocale::Script::ThaiScript:
+        return QFontDatabase::WritingSystem::Thai;
+    case QLocale::Script::TibetanScript:
+        return QFontDatabase::WritingSystem::Tibetan;
+    case QLocale::Script::SimplifiedChineseScript:
+        return QFontDatabase::WritingSystem::SimplifiedChinese;
+    case QLocale::Script::TraditionalChineseScript:
+        return QFontDatabase::WritingSystem::TraditionalChinese;
+
+    default:
+        qWarning() << "Unknown script" << script;
+        return QFontDatabase::WritingSystem::Any;
+    }
+}
+
 } // namespace
 
 /**
  * @class GeneralForm
  *
  * This form contains all settings that are not suited to other forms
  */
-GeneralForm::GeneralForm(SettingsWidget* myParent, Settings& settings_, Style& style)
+GeneralForm::GeneralForm(Settings& settings_, Style& style)
     : GenericForm(QPixmap(":/img/settings/general.png"), style)
-    , bodyUI(new Ui::GeneralSettings)
+    , bodyUI{new Ui::GeneralSettings}
     , settings{settings_}
 {
-    parent = myParent;
-
     bodyUI->setupUi(this);
 
     // block all child signals during initialization
@@ -107,16 +171,20 @@ GeneralForm::GeneralForm(SettingsWidget* myParent, Settings& settings_, Style& s
     for (int i = 0; i < locales.size(); ++i) {
         QString langName;
 
-        if (locales[i].startsWith(QLatin1String("eo"))) // QTBUG-57802
-            langName = QLocale::languageToString(QLocale::Esperanto);
-        else if (locales[i].startsWith(QLatin1String("jbo")))
+        if (locales[i].startsWith(QLatin1String("jbo")))
             langName = QLatin1String("Lojban");
         else if (locales[i].startsWith(QLatin1String("pr")))
             langName = QLatin1String("Pirate");
-        else if (locales[i] == (QLatin1String("pt"))) // QTBUG-47891
-            langName = QStringLiteral("português");
-        else
-            langName = QLocale(locales[i]).nativeLanguageName();
+        else {
+            const QLocale locale{locales[i]};
+            if (!QFontDatabase::families(writingSystem(locale.script())).isEmpty())
+                langName = locale.nativeLanguageName();
+            else
+                langName = tr("%1 (no fonts)").arg(QLocale::languageToString(locale.language()));
+            if (langName.isEmpty()) {
+                langName = QLocale::languageToString(locale.language());
+            }
+        }
 
         bodyUI->transComboBox->insertItem(i, langName);
     }
@@ -146,7 +214,6 @@ GeneralForm::GeneralForm(SettingsWidget* myParent, Settings& settings_, Style& s
                                           / 1024 / 1024);
     bodyUI->autoacceptFiles->setChecked(settings.getAutoSaveEnabled());
 
-
 #ifndef QTOX_PLATFORM_EXT
     bodyUI->autoAwayLabel->setEnabled(false); // these don't seem to change the appearance of the widgets,
     bodyUI->autoAwaySpinBox->setEnabled(false); // though they are unusable
@@ -159,7 +226,6 @@ GeneralForm::GeneralForm(SettingsWidget* myParent, Settings& settings_, Style& s
 GeneralForm::~GeneralForm()
 {
     Translator::unregister(this);
-    delete bodyUI;
 }
 
 void GeneralForm::on_transComboBox_currentIndexChanged(int index)

src/widget/form/settings/generalform.h

@@ -19,7 +19,7 @@ class GeneralForm : public GenericForm
 {
     Q_OBJECT
 public:
-    GeneralForm(SettingsWidget* parent, Settings& settings, Style& style);
+    GeneralForm(Settings& settings, Style& style);
     ~GeneralForm();
     QString getFormName() final
     {
@@ -49,7 +49,6 @@ private slots:
     void retranslateUi();
 
 private:
-    Ui::GeneralSettings* bodyUI;
-    SettingsWidget* parent;
+    const std::unique_ptr<Ui::GeneralSettings> bodyUI;
     Settings& settings;
 };

src/widget/form/settingswidget.cpp

@@ -45,7 +45,7 @@ SettingsWidget::SettingsWidget(UpdateCheck* updateCheck, IAudioControl& audio, C
     settingsWidgets->setTabPosition(QTabWidget::North);
     bodyLayout->addWidget(settingsWidgets.get());
 
-    std::unique_ptr<GeneralForm> gfrm(new GeneralForm(this, settings, style));
+    std::unique_ptr<GeneralForm> gfrm(new GeneralForm(settings, style));
     connect(gfrm.get(), &GeneralForm::updateIcons, parent, &Widget::updateIcons);
 
     std::unique_ptr<UserInterfaceForm> uifrm(new UserInterfaceForm(smileyPack, settings, style, this));

translations/ar.ts

@@ -1083,6 +1083,10 @@ so you can save the file on Windows.</source>
         <source>General</source>
         <translation>عام</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/be.ts

@@ -1087,6 +1087,10 @@ so you can save the file on Windows.</source>
         <comment>popup title</comment>
         <translation>Выбраць каталог для аўтаматычна прынятых файлаў</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/bg.ts

@@ -1085,6 +1085,10 @@ so you can save the file on Windows.</source>
         <comment>popup title</comment>
         <translation>Изберете папка за автоматично приемане</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/bn.ts

@@ -1082,6 +1082,10 @@ so you can save the file on Windows.</source>
         <comment>popup title</comment>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/cs.ts

@@ -1085,6 +1085,10 @@ takže můžete soubor uložit i v systému Windows.</translation>
         <source>General</source>
         <translation>Obecné</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/da.ts

@@ -1085,6 +1085,10 @@ so you can save the file on Windows.</source>
         <comment>popup title</comment>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/de.ts

@@ -1091,6 +1091,10 @@ um sie in Windows speichern zu können.</translation>
         <comment>popup title</comment>
         <translation>Speicherort für empfangenen Dateien wählen</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/el.ts

@@ -1079,6 +1079,10 @@ so you can save the file on Windows.</source>
         <source>General</source>
         <translation>Γενικά</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/eo.ts

@@ -1075,6 +1075,10 @@ so you can save the file on Windows.</source>
         <source>General</source>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/es.ts

@@ -1085,6 +1085,10 @@ para que puedas guardar el archivo en windows.</translation>
         <comment>popup title</comment>
         <translation>Elige un directorio para transferencias automáticas</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/et.ts

@@ -1085,6 +1085,10 @@ ja sa saad seda faili nüüd Windowsis salvestada.</translation>
         <source>General</source>
         <translation>Üldine</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/fa.ts

@@ -1085,6 +1085,10 @@ so you can save the file on Windows.</source>
         <comment>popup title</comment>
         <translation>یک پوشه برای دریافت فایلها به شکل خودکار انتخاب کنید</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/fi.ts

@@ -1084,6 +1084,10 @@ joten voit tallentaa tiedoston Windowsissa.</translation>
         <comment>popup title</comment>
         <translation>Valitse hakemisto automaattisesti hyväksyttäville tiedostoille</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/fr.ts

@@ -1084,6 +1084,10 @@ afin que vous puissiez enregistrer le fichier sur windows.</translation>
         <comment>popup title</comment>
         <translation>Sélectionner un répertoire d&apos;acceptation automatique</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/gl.ts

@@ -1086,6 +1086,10 @@ so you can save the file on Windows.</source>
         <comment>popup title</comment>
         <translation>Elixa un cartafol para aceptados automáticamente</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/he.ts

@@ -1082,6 +1082,10 @@ so you can save the file on Windows.</source>
         <comment>popup title</comment>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/hr.ts

@@ -1080,6 +1080,10 @@ so you can save the file on Windows.</source>
         <comment>popup title</comment>
         <translation>Odaberi direktorij za automatsko prihvaćanje</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/hu.ts

@@ -1078,6 +1078,10 @@ so you can save the file on Windows.</source>
         <comment>popup title</comment>
         <translation>Válasszon egy mappát az automatikus elfogadáshoz</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/is.ts

@@ -1082,6 +1082,10 @@ so you can save the file on Windows.</source>
         <comment>popup title</comment>
         <translation type="unfinished"></translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/it.ts

@@ -1084,6 +1084,10 @@ in modo da poter salvare il file su Windows.</translation>
         <comment>popup title</comment>
         <translation>Scegli dove salvare i file accettati automaticamente</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>

translations/ja.ts

@@ -1078,6 +1078,10 @@ so you can save the file on Windows.</source>
         <source>General</source>
         <translation>一般</translation>
     </message>
+    <message>
+        <source>%1 (no fonts)</source>
+        <translation type="unfinished"></translation>
+    </message>
 </context>
 <context>
     <name>GeneralSettings</name>