language: Fix codepage used for Inno Setup 4.0.0 to 4.2.2

Currently the codepage is only used to decode messages and the language
name.

src/setup/language.cpp

@@ -20,11 +20,105 @@
 
 #include "setup/language.hpp"
 
+#include <algorithm>
+
+#include "boost/range/begin.hpp"
+#include "boost/range/end.hpp"
+
 #include "setup/version.hpp"
 #include "util/load.hpp"
 
 namespace setup {
 
+namespace {
+
+struct windows_language {
+	
+	boost::uint16_t language_id;
+	boost::uint16_t codepage;
+	
+	bool operator<(boost::uint32_t language) {
+		return language_id < language;
+	}
+	
+};
+
+/*
+ * Sorted list of Windows language IDs with their default ANSI codepages.
+ * This list omits unicode-only languages and languages using the default Windows-1252 codepage.
+ */
+windows_language languages[] = {
+	{ 0x0401, 1256 },
+	{ 0x0402, 1251 },
+	{ 0x0404, 950 },
+	{ 0x0405, 1250 },
+	{ 0x0408, 1253 },
+	{ 0x040d, 1255 },
+	{ 0x040e, 1250 },
+	{ 0x0411, 932 },
+	{ 0x0412, 949 },
+	{ 0x0415, 1250 },
+	{ 0x0418, 1250 },
+	{ 0x0419, 1251 },
+	{ 0x041a, 1250 },
+	{ 0x041b, 1250 },
+	{ 0x041c, 1250 },
+	{ 0x041e, 874 },
+	{ 0x041f, 1254 },
+	{ 0x0420, 1256 },
+	{ 0x0422, 1251 },
+	{ 0x0423, 1251 },
+	{ 0x0424, 1250 },
+	{ 0x0425, 1257 },
+	{ 0x0426, 1257 },
+	{ 0x0427, 1257 },
+	{ 0x0429, 1256 },
+	{ 0x042a, 1258 },
+	{ 0x042c, 1254 },
+	{ 0x042f, 1251 },
+	{ 0x043f, 1251 },
+	{ 0x0440, 1251 },
+	{ 0x0443, 1254 },
+	{ 0x0444, 1251 },
+	{ 0x0450, 1251 },
+	{ 0x0492, 28604 },
+	{ 0x0801, 1256 },
+	{ 0x0804, 936 },
+	{ 0x081a, 1250 },
+	{ 0x082c, 1251 },
+	{ 0x0843, 1251 },
+	{ 0x0c01, 1256 },
+	{ 0x0c04, 950 },
+	{ 0x0c1a, 1251 },
+	{ 0x1001, 1256 },
+	{ 0x1004, 936 },
+	{ 0x1401, 1256 },
+	{ 0x1404, 950 },
+	{ 0x1801, 1256 },
+	{ 0x1c01, 1256 },
+	{ 0x2001, 1256 },
+	{ 0x2401, 1256 },
+	{ 0x2801, 1256 },
+	{ 0x2c01, 1256 },
+	{ 0x3001, 1256 },
+	{ 0x3401, 1256 },
+	{ 0x3801, 1256 },
+	{ 0x3c01, 1256 },
+	{ 0x4001, 1256 },
+};
+
+util::codepage_id default_codepage_for_language(boost::uint32_t language) {
+	
+	windows_language * entry = std::lower_bound(boost::begin(languages), boost::end(languages), language);
+	if(entry != boost::end(languages) && entry->language_id == language) {
+		return entry->codepage;
+	}
+	
+	return util::cp_windows1252;
+}
+
+} // anonymous namespace
+
 void language_entry::load(std::istream & is, const version & version) {
 	
 	if(version >= INNO_VERSION(4, 0, 0)) {
@@ -33,7 +127,7 @@ void language_entry::load(std::istream & is, const version & version) {
 		name = "default";
 	}
 	
-	is >> util::encoded_string(language_name, (version >= INNO_VERSION(4, 2, 2)) ? 1200u : 1252u);
+	is >> util::binary_string(language_name);
 	
 	if(version == INNO_VERSION_EXT(5, 5,  7, 1)) {
 		util::load<boost::uint32_t>(is); // always 0?
@@ -58,13 +152,21 @@ void language_entry::load(std::istream & is, const version & version) {
 	
 	language_id = util::load<boost::uint32_t>(is);
 	
-	if(version >= INNO_VERSION(4, 2, 2) && (version < INNO_VERSION(5, 3, 0) || !version.is_unicode())) {
+	if(version < INNO_VERSION(4, 2, 2)) {
+		codepage = default_codepage_for_language(language_id);
+	} else if(version < INNO_VERSION(5, 3, 0) || !version.is_unicode()) {
 		codepage = util::load<boost::uint32_t>(is);
+		if(!codepage) {
+			codepage = version.codepage();
+		}
 	} else {
-		codepage = 0;
+		codepage = util::cp_utf16le;
 	}
-	if(!codepage) {
-		codepage = version.codepage();
+	
+	if(version >= INNO_VERSION(4, 2, 2)) {
+		util::to_utf8(language_name, util::cp_utf16le);
+	} else {
+		util::to_utf8(language_name, codepage);
 	}
 	
 	dialog_font_size = util::load<boost::uint32_t>(is);