[core] Fix local language not being used in some cases

Signed-off-by: Yannik Bloscheck <git@yannikbloscheck.com>

indexer/feature_utils.cpp

@@ -128,34 +128,50 @@ bool IsNativeLang(feature::RegionData const & regionData, int8_t deviceLang)
   return false;
 }
 
-vector<int8_t> MakeLanguagesPriorityList(int8_t deviceLang, bool preferDefault)
+int8_t DefaultLanguage(feature::RegionData const & regionData, vector<int8_t> langs)
 {
-  vector<int8_t> langPriority = {deviceLang};
-  for (auto const & lang : languages::GetPreferredLangIndexes())
+  for (auto const lang : langs)
   {
-    if (find(langPriority.begin(), langPriority.end(), lang) == langPriority.end())
+    if (regionData.HasLanguage(lang))
+      return lang;
+
+    for (auto const similiarLang : GetSimilarLanguages(lang))
     {
-      langPriority.push_back(lang);
+      if (regionData.HasLanguage(similiarLang))
+        return similiarLang;
     }
   }
-  
-  if (preferDefault)
-    langPriority.push_back(StrUtf8::kDefaultCode);
 
-  /// @DebugNote
-  // Add ru lang for descriptions/rendering tests.
-  //langPriority.push_back(StrUtf8::GetLangIndex("ru"));
+  return StrUtf8::kDefaultCode;
+}
 
-  auto const similarLangs = GetSimilarLanguages(deviceLang);
-  langPriority.insert(langPriority.cend(), similarLangs.cbegin(), similarLangs.cend());
-  langPriority.insert(langPriority.cend(), {StrUtf8::kInternationalCode, StrUtf8::kEnglishCode});
+vector<int8_t> PrioritizedLanguages(vector<int8_t> const & langs, int8_t defaultLang)
+{
+  vector<int8_t> prioritizedLangs = {};
 
-  return langPriority;
+  for (auto const lang : langs)
+  {
+    if (find(prioritizedLangs.begin(), prioritizedLangs.end(), lang) == prioritizedLangs.end())
+      prioritizedLangs.push_back(lang);
+      
+    if (defaultLang != StrUtf8::kUnsupportedLanguageCode && defaultLang == lang)
+      prioritizedLangs.push_back(StrUtf8::kDefaultCode);
+    
+    auto const similarLangs = GetSimilarLanguages(lang);
+    prioritizedLangs.insert(prioritizedLangs.cend(), similarLangs.cbegin(), similarLangs.cend());
+  }
+
+  prioritizedLangs.push_back(StrUtf8::kInternationalCode);
+  prioritizedLangs.push_back(StrUtf8::kEnglishCode);
+  prioritizedLangs.push_back(StrUtf8::kDefaultCode);
+
+  return prioritizedLangs;
 }
 
 void GetReadableNameImpl(NameParamsIn const & in, bool preferDefault, NameParamsOut & out)
 {
-  auto const langPriority = MakeLanguagesPriorityList(in.deviceLang, preferDefault);
+  auto const preferredLangs = languages::GetPreferredLangIndexes();
+  auto const langPriority = PrioritizedLanguages(preferredLangs, DefaultLanguage(in.regionData, preferredLangs));
 
   if (GetBestName(in.src, langPriority, out.primary))
     return;
@@ -361,7 +377,8 @@ void GetPreferredNames(NameParamsIn const & in, NameParamsOut & out)
   if (in.IsNativeOrSimilarLang())
     return GetReadableNameImpl(in, true /* preferDefault */, out);
 
-  auto const primaryCodes = MakeLanguagesPriorityList(in.deviceLang, false /* preferDefault */);
+  auto const preferredLangs = languages::GetPreferredLangIndexes();
+  auto const primaryCodes = PrioritizedLanguages(preferredLangs, DefaultLanguage(in.regionData, preferredLangs));
 
   if (!GetBestName(in.src, primaryCodes, out.primary) && in.allowTranslit)
     GetTransliteratedName(in.regionData, in.src, out.transliterated);
@@ -426,14 +443,15 @@ int8_t GetNameForSearchOnBooking(RegionData const & regionData, StringUtf8Multil
 
 bool GetPreferredName(StringUtf8Multilang const & src, int8_t deviceLang, string_view & out)
 {
-  auto const priorityList = MakeLanguagesPriorityList(deviceLang, true /* preferDefault */);
+  auto const preferredLangs = languages::GetPreferredLangIndexes();
+  auto const priorityList = PrioritizedLanguages(preferredLangs, StrUtf8::kUnsupportedLanguageCode);
   return GetBestName(src, priorityList, out);
 }
 
-vector<int8_t> GetDescriptionLangPriority(RegionData const & regionData, int8_t const deviceLang)
+vector<int8_t> GetDescriptionLangPriority(RegionData const & regionData)
 {
-  bool const preferDefault = IsNativeLang(regionData, deviceLang);
-  return MakeLanguagesPriorityList(deviceLang, preferDefault);
+  auto const preferredLangs = languages::GetPreferredLangIndexes();
+  return PrioritizedLanguages(preferredLangs, DefaultLanguage(regionData, preferredLangs));
 }
 
 vector<string> GetCuisines(TypesHolder const & types)

indexer/feature_utils.hpp

@@ -136,12 +136,13 @@ namespace feature
 
   /// Returns priority list of language codes for feature description,
   /// the priority is the following:
-  /// - device language code;
-  /// - default language code if MWM contains user's language (or similar to device languages if provided);
-  /// - languages that we know are similar to device language;
+  /// - device language codes in order of preference;
+  ///   - including default language code, if MWM contains the language (or similar to device language if provided);
+  ///   - including languages that we know are similar to device language;
   /// - international language code;
   /// - english language code;
-  std::vector<int8_t> GetDescriptionLangPriority(RegionData const & regionData, int8_t const deviceLang);
+  /// - default language code;
+  std::vector<int8_t> GetDescriptionLangPriority(RegionData const & regionData);
 
   // Returns vector of cuisines readable names from classificator.
   std::vector<std::string> GetCuisines(TypesHolder const & types);

map/framework.cpp

@@ -3339,8 +3339,7 @@ void Framework::FillDescription(FeatureType & ft, place_page::Info & info) const
   if (!ft.GetID().m_mwmId.IsAlive())
     return;
   auto const & regionData = ft.GetID().m_mwmId.GetInfo()->GetRegionData();
-  auto const deviceLang = StringUtf8Multilang::GetLangIndex(languages::GetCurrentMapLanguage());
-  auto const langPriority = feature::GetDescriptionLangPriority(regionData, deviceLang);
+  auto const langPriority = feature::GetDescriptionLangPriority(regionData);
 
   std::string wikiDescription = m_descriptionsLoader->GetWikiDescription(ft.GetID(), langPriority);
   if (!wikiDescription.empty())

platform/preferred_languages.cpp

@@ -191,6 +191,11 @@ std::string GetCurrentMapLanguage()
 std::vector<int8_t> GetPreferredLangIndexes()
 {
   std::vector<int8_t> langs = {};
+  
+  auto const mapLang = StringUtf8Multilang::GetLangIndex(languages::GetCurrentMapLanguage());
+  if (mapLang != StringUtf8Multilang::kUnsupportedLanguageCode)
+    langs.push_back(mapLang);
+  
   for (auto const & systemLanguage : GetSystemPreferred())
   {
     auto normalizedLang = Normalize(systemLanguage);