AGS: Skeleton for converting UTF-8 translation keys to ASCII

From upstream e04f86a91b248f598fccf04369e0874393a9a45d

Upstream uses locale, but since that isn't available to a
ScummVM engine, for now it's just a skeleton implementation

engines/ags/engine/ac/translation.cpp

@@ -20,6 +20,7 @@
  *
  */
 
+#include "common/language.h"
 #include "ags/engine/ac/asset_helper.h"
 #include "ags/shared/ac/common.h"
 #include "ags/engine/ac/game_setup.h"
@@ -40,6 +41,13 @@ namespace AGS3 {
 
 using namespace AGS::Shared;
 
+// TODO: Since ScummVM can't use uconvert, this is a dummy implementation for now
+const char *convert_utf8_to_ascii(const char *mbstr, const char *loc_name) {
+	_G(mbbuf).resize(strlen(mbstr) + 1);
+	strcpy(&_G(mbbuf)[0], mbstr);
+	return &_G(mbbuf)[0];
+}
+
 void close_translation() {
 	_GP(transtree).clear();
 	_GP(trans) = Translation();
@@ -111,6 +119,22 @@ bool init_translation(const String &lang, const String &fallback_lang, bool quit
 	else
 		set_uformat(U_ASCII);
 
+	// Mixed encoding support: 
+	// original text unfortunately may contain extended ASCII chars (> 127);
+	// if translation is UTF-8 but game is extended ASCII, then the translation
+	// dictionary keys won't match.
+	// With that assumption we must convert dictionary keys into ASCII using
+	// provided locale hint.
+	String key_enc = _GP(trans).StrOptions["gameencoding"];
+	if (!key_enc.IsEmpty()) {
+		StringMap conv_map;
+		for (const auto &item : _GP(trans).Dict) {
+			String key = convert_utf8_to_ascii(item._key.GetCStr(), key_enc.GetCStr());
+			conv_map.insert(std::make_pair(key, item._value));
+		}
+		_GP(trans).Dict = conv_map;
+	}
+
 	Debug::Printf("Translation initialized: %s", _G(trans_filename).GetCStr());
 	return true;
 }

engines/ags/globals.h

@@ -1319,6 +1319,8 @@ public:
 	String _trans_name, _trans_filename;
 	long _lang_offs_start = 0;
 	char _transFileName[MAX_PATH] = { 0 };
+	std::vector<uint16> _wcsbuf; // widechar buffer
+	std::vector<char> _mbbuf;  // utf8 buffer
 
 	/**@}*/