mirror/transmission
1
0
Fork 0
mirror of https://github.com/transmission/transmission synced 2025-01-30 10:52:00 +00:00
Code Issues Releases Wiki Activity

fix: escaped representation of non-BMP characters when generating JSON (#5096)

Browse source
This commit is contained in:
Daniel Kamil Kozar 2023-03-02 07:55:16 +01:00 committed by GitHub
parent 8fc904617b
commit 848212eea1
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
2 changed files with 86 additions and 29 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

94
libtransmission/variant-json.cc
View file

@ -132,7 +132,7 @@ void action_callback_PUSH(jsonsl_t jsn, jsonsl_action_t /*action*/, struct jsons
}
/* like sscanf(in+2, "%4x", &val) but less slow */
[[nodiscard]] constexpr bool decode_hex_string(char const* in, unsigned int* setme)
[[nodiscard]] constexpr bool decode_hex_string(char const* in, std::uint16_t& setme)
{
TR_ASSERT(in != nullptr);
@ -165,7 +165,46 @@ void action_callback_PUSH(jsonsl_t jsn, jsonsl_action_t /*action*/, struct jsons
}
} while (++in != end);
*setme = val;
setme = val;
return true;
}
template<typename Iter>
void decode_single_uchar(char const*& in, char const* const in_end, Iter& buf16_out_it)
{
static auto constexpr EscapedUcharLength = 6U;
if (in_end - in >= EscapedUcharLength && decode_hex_string(in, *buf16_out_it))
{
in += EscapedUcharLength;
++buf16_out_it;
}
}
[[nodiscard]] bool decode_escaped_uchar_sequence(char const*& in, char const* const in_end, std::string& buf)
{
auto buf16 = std::array<std::uint16_t, 2>{};
auto buf16_out_it = std::begin(buf16);
decode_single_uchar(in, in_end, buf16_out_it);
if (in[0] == '\\' && in[1] == 'u')
{
decode_single_uchar(in, in_end, buf16_out_it);
}
if (buf16_out_it == std::begin(buf16))
{
return false;
}
try
{
utf8::utf16to8(std::begin(buf16), buf16_out_it, std::back_inserter(buf));
}
catch (utf8::exception const&) // invalid codepoint
{
buf.push_back('?');
}
return true;
}
@ -232,26 +271,10 @@ void action_callback_PUSH(jsonsl_t jsn, jsonsl_action_t /*action*/, struct jsons
break;
case 'u':
if (in_end - in >= 6)
if (decode_escaped_uchar_sequence(in, in_end, buf))
{
unsigned int val = 0;
if (decode_hex_string(in, &val))
{
try
{
auto buf8 = std::array<char, 8>{};
auto const it = utf8::append(val, std::data(buf8));
buf.append(std::data(buf8), it - std::data(buf8));
}
catch (utf8::exception const&) // invalid codepoint
{
buf.push_back('?');
}
unescaped = true;
in += 6;
break;
}
unescaped = true;
break;
}
}
}
@ -541,6 +564,26 @@ void jsonRealFunc(tr_variant const* val, void* vdata)
jsonChildFunc(data);
}
void write_escaped_char(Buffer& out, std::string_view& sv)
{
auto u16buf = std::array<std::uint16_t, 2>{};
auto const* const begin8 = std::data(sv);
auto const* const end8 = begin8 + std::size(sv);
auto const* walk8 = begin8;
utf8::next(walk8, end8);
auto const end16 = utf8::utf8to16(begin8, walk8, std::begin(u16buf));
for (auto it = std::cbegin(u16buf); it != end16; ++it)
{
auto arr = std::array<char, 16>{};
auto const result = fmt::format_to_n(std::data(arr), std::size(arr), FMT_COMPILE("\\u{:04x}"), *it);
out.add(std::data(arr), result.size);
}
sv.remove_prefix(walk8 - begin8 - 1);
}
void jsonStringFunc(tr_variant const* val, void* vdata)
{
auto* data = static_cast<struct JsonWalk*>(vdata);
@ -593,14 +636,7 @@ void jsonStringFunc(tr_variant const* val, void* vdata)
{
try
{
auto arr = std::array<char, 16>{};
auto const* const begin8 = std::data(sv);
auto const* const end8 = begin8 + std::size(sv);
auto const* walk8 = begin8;
auto const uch32 = utf8::next(walk8, end8);
auto const result = fmt::format_to_n(std::data(arr), std::size(arr), FMT_COMPILE("\\u{:04x}"), uch32);
out.add(std::data(arr), result.size);
sv.remove_prefix(walk8 - begin8 - 1);
write_escaped_char(out, sv);
}
catch (utf8::exception const&)
{

21
tests/libtransmission/json-test.cc
View file

@ -121,6 +121,27 @@ TEST_P(JSONTest, testUtf8)
tr_variantClear(&top);
}
TEST_P(JSONTest, testUtf16Surrogates)
{
static auto constexpr ThinkingFaceEmojiUtf8 = "\xf0\x9f\xa4\x94"sv;
auto top = tr_variant{};
tr_variantInitDict(&top, 1);
auto const key = tr_quark_new("key"sv);
tr_variantDictAddStr(&top, key, ThinkingFaceEmojiUtf8);
auto const json = tr_variantToStr(&top, TR_VARIANT_FMT_JSON_LEAN);
EXPECT_NE(std::string::npos, json.find("ud83e"));
EXPECT_NE(std::string::npos, json.find("udd14"));
tr_variantClear(&top);
auto parsed = tr_variant{};
EXPECT_TRUE(tr_variantFromBuf(&parsed, TR_VARIANT_PARSE_JSON | TR_VARIANT_PARSE_INPLACE, json));
EXPECT_TRUE(tr_variantIsDict(&parsed));
auto value = std::string_view{};
EXPECT_TRUE(tr_variantDictFindStrView(&parsed, key, &value));
EXPECT_EQ(ThinkingFaceEmojiUtf8, value);
tr_variantClear(&parsed);
}
TEST_P(JSONTest, test1)
{
auto const in = std::string{