--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/zxing-cpp/core/src/CharacterSet.cpp	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,91 @@
+/*
+* Copyright 2016 Nu-book Inc.
+* Copyright 2016 ZXing authors
+*/
+// SPDX-License-Identifier: Apache-2.0
+
+#include "CharacterSet.h"
+
+#include "ZXAlgorithms.h"
+
+#include <algorithm>
+#include <cctype>
+
+namespace ZXing {
+
+struct CharacterSetName
+{
+	std::string_view name;
+	CharacterSet cs;
+};
+
+static CharacterSetName NAME_TO_CHARSET[] = {
+	{"Cp437",		CharacterSet::Cp437},
+	{"ISO-8859-1",	CharacterSet::ISO8859_1},
+	{"ISO-8859-2",	CharacterSet::ISO8859_2},
+	{"ISO-8859-3",	CharacterSet::ISO8859_3},
+	{"ISO-8859-4",	CharacterSet::ISO8859_4},
+	{"ISO-8859-5",	CharacterSet::ISO8859_5},
+	{"ISO-8859-6",	CharacterSet::ISO8859_6},
+	{"ISO-8859-7",	CharacterSet::ISO8859_7},
+	{"ISO-8859-8",	CharacterSet::ISO8859_8},
+	{"ISO-8859-9",	CharacterSet::ISO8859_9},
+	{"ISO-8859-10",	CharacterSet::ISO8859_10},
+	{"ISO-8859-11",	CharacterSet::ISO8859_11},
+	{"ISO-8859-13",	CharacterSet::ISO8859_13},
+	{"ISO-8859-14",	CharacterSet::ISO8859_14},
+	{"ISO-8859-15",	CharacterSet::ISO8859_15},
+	{"ISO-8859-16",	CharacterSet::ISO8859_16},
+	{"SJIS",		CharacterSet::Shift_JIS},
+	{"Shift_JIS",	CharacterSet::Shift_JIS},
+	{"Cp1250",		CharacterSet::Cp1250},
+	{"windows-1250",CharacterSet::Cp1250},
+	{"Cp1251",		CharacterSet::Cp1251},
+	{"windows-1251",CharacterSet::Cp1251},
+	{"Cp1252",		CharacterSet::Cp1252},
+	{"windows-1252",CharacterSet::Cp1252},
+	{"Cp1256",		CharacterSet::Cp1256},
+	{"windows-1256",CharacterSet::Cp1256},
+	{"UTF-16BE",	CharacterSet::UTF16BE},
+	{"UTF-16LE",	CharacterSet::UTF16LE},
+	{"UTF-32BE",	CharacterSet::UTF32BE},
+	{"UTF-32LE",	CharacterSet::UTF32LE},
+	{"UnicodeBigUnmarked", CharacterSet::UTF16BE},
+	{"UnicodeBig",	CharacterSet::UTF16BE},
+	{"UTF-8",		CharacterSet::UTF8},
+	{"ASCII",		CharacterSet::ASCII},
+	{"US-ASCII",	CharacterSet::ASCII},
+	{"Big5",		CharacterSet::Big5},
+	{"GB2312",		CharacterSet::GB2312},
+	{"GB18030",		CharacterSet::GB18030},
+	{"EUC-CN",		CharacterSet::GB18030},
+	{"GBK",			CharacterSet::GB18030},
+	{"EUC-KR",		CharacterSet::EUC_KR},
+	{"BINARY",		CharacterSet::BINARY},
+};
+
+static std::string NormalizeName(std::string_view sv)
+{
+	std::string str(sv);
+	std::transform(str.begin(), str.end(), str.begin(), [](char c) { return (char)std::tolower(c); });
+#ifdef __cpp_lib_erase_if
+	std::erase_if(str, [](char c) { return Contains("_-[] ", c); });
+#else
+	str.erase(std::remove_if(str.begin(), str.end(), [](char c) { return Contains("_-[] ", c); }), str.end());
+#endif
+	return str;
+}
+
+CharacterSet CharacterSetFromString(std::string_view name)
+{
+	auto i = FindIf(NAME_TO_CHARSET, [str = NormalizeName(name)](auto& v) { return NormalizeName(v.name) == str; });
+	return i == std::end(NAME_TO_CHARSET) ? CharacterSet::Unknown : i->cs;
+}
+
+std::string ToString(CharacterSet cs)
+{
+	auto i = FindIf(NAME_TO_CHARSET, [cs](auto& v) { return v.cs == cs; });
+	return i == std::end(NAME_TO_CHARSET) ? "" : std::string(i->name);
+}
+
+} // namespace ZXing