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Fix remote edit crash #436

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Fix remote edit crash #436

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8fab660
report if sendToUser() is missing a newline
nschimme Dec 21, 2025
89df0d5
bugfix bad format argument and missing newline
nschimme Dec 22, 2025
942fae3
bugfix for QChar::toLatin1() returning C_NUL
nschimme Dec 21, 2025
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49 changes: 40 additions & 9 deletions src/global/Charset.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -59,6 +59,7 @@ using namespace string_consts;
X(0x201Eu, C_DQUOTE, "bdquo") XSEP() \
X(0x201Fu, C_DQUOTE, "double high reversed quotation mark") XSEP() \
X(0x2022u, C_ASTERISK, "bull") XSEP() \
X(0x202Fu, C_NBSP, "nnbsp") XSEP() \
X(0x2039u, C_LESS_THAN, "lsaquo") XSEP() \
X(0x203Au, C_GREATER_THAN, "rsaquo")

Expand All @@ -76,12 +77,10 @@ NODISCARD constexpr bool is_latin_control(const T uc)
&& (uc >= 0x80u && uc < 0xA0u); // Latin1 control character
}
template<typename T>
NODISCARD constexpr bool is_noncontrol_ascii(const T ascii)
NODISCARD constexpr bool is_noncontrol_latin1(const T byte)
{
// non-control ASCII
return std::is_same_v<char, T> //
&& (static_cast<uint8_t>(ascii) & 0x7Fu) == static_cast<uint8_t>(ascii) //
&& static_cast<uint8_t>(ascii) >= 0x20u; //
return std::is_same_v<char, T> && !is_latin_control(static_cast<uint8_t>(byte));
Comment on lines +80 to +83
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@sourcery-ai sourcery-ai bot Dec 22, 2025

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issue (bug_risk): The new is_noncontrol_latin1 no longer enforces the non-control range invariant due to a type mismatch with is_latin_control.

is_noncontrol_ascii previously guaranteed _ascii was a non-control ASCII char (0x20–0x7F). In the new version, is_latin_control is constrained to T == char16_t, but here T is deduced as uint8_t, so is_latin_control(static_cast<uint8_t>(byte)) is never actually called and effectively always yields false. The condition then collapses to std::is_same_v<char, T>, so static_assert(is_noncontrol_latin1(_ascii)); no longer excludes Latin1 control bytes or out-of-range values. To preserve the invariant, either add an 8-bit overload of is_latin_control or restore an explicit range check on the uint8_t value.

}
template<typename T>
NODISCARD constexpr bool is_16bit_unicode(const T uc)
Expand All @@ -98,7 +97,7 @@ XFOREACH_WINDOWS_125x(XCASE, XSEMI);
#undef XCASE

#define XCASE(_unicode, _ascii, _name) \
static_assert(is_noncontrol_ascii(_ascii)); \
static_assert(is_noncontrol_latin1(_ascii)); \
static_assert(is_16bit_unicode(_unicode))
XFOREACH_UNICODE_TRANSLIT(XCASE, XSEMI);
#undef XCASE
Expand Down Expand Up @@ -194,8 +193,7 @@ NODISCARD static constexpr char16_t simple_unicode_translit(const char16_t input
case (_unicode): \
return conversion::to_char16(_ascii)

const auto maybe_bigger = windows125x_to_unicode(input);
switch (maybe_bigger) {
switch (MAYBE_UNUSED const auto maybe_bigger = windows125x_to_unicode(input)) {
XFOREACH_UNICODE_TRANSLIT(XCASE, XSEMI);
default:
return input;
Expand Down Expand Up @@ -297,6 +295,23 @@ NODISCARD QChar simple_unicode_translit(const QChar qc) noexcept
return QChar{charset::simple_unicode_translit(static_cast<char16_t>(qc.unicode()))};
}

NODISCARD static bool isValidLatin1(char latin1)
{
// Eventually we may want to exclude some other ASCII control codes,
// but be careful not to exclude things like "\t\r\n".
return latin1 != C_NUL && !is_latin_control(latin1);
Comment on lines +298 to +302
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@sourcery-ai sourcery-ai bot Dec 22, 2025

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issue (bug_risk): isValidLatin1 also relies on is_latin_control with a mismatched type, so Latin1 control characters will be treated as valid.

Here latin1 is a char, so this calls is_latin_control<char>, whose implementation always returns false because it only handles char16_t. As a result, isValidLatin1 only rejects C_NUL and treats all Latin1 control characters (0x80–0x9F) as valid. To actually filter those controls, cast to a 16-bit type (e.g. char16_t) before calling is_latin_control, or add a dedicated 8-bit overload and use it consistently (including in is_noncontrol_latin1).

}

NODISCARD static QLatin1Char toQLatin1Char(const QChar input)
{
const QChar qc = mmqt::simple_unicode_translit(input);
if (const char latin1 = qc.toLatin1(); isValidLatin1(latin1)) {
return QLatin1Char{latin1};
} else {
return QLatin1Char{'?'};
}
}

ALLOW_DISCARD QString &toLatin1InPlace(QString &str)
{
if (containsAnySurrogates(str)) {
Expand All @@ -308,8 +323,7 @@ ALLOW_DISCARD QString &toLatin1InPlace(QString &str)
}

for (QChar &qc : str) {
mmqt::simple_unicode_translit_in_place(qc);
qc = QLatin1Char{qc.toLatin1()};
qc = mmqt::toQLatin1Char(qc);
}
return str;
}
Expand Down Expand Up @@ -978,6 +992,23 @@ void testStringsExtreme()

void testMmqtLatin1()
{
{
const QString narrowNbspStr{"\U0000202F"}; // NNBSP (narrow NBSP)
{
const auto latin1 = mmqt::toLatin1(narrowNbspStr);
TEST_ASSERT(latin1 == mmqt::QS_NBSP);
}
{
// thumbs up uses a surrogate pair, which forces mmqt::toLatin1() to call
// a different code path.
const auto thumbsUpStr = QString{"\U0001F44D"};
const QString input = narrowNbspStr + mmqt::QS_COMMA + thumbsUpStr + mmqt::QS_NEWLINE;
const QString expect = mmqt::QS_NBSP + mmqt::QS_COMMA + mmqt::QS_QUESTION_MARK
+ mmqt::QS_NEWLINE;
const auto latin1 = mmqt::toLatin1(input);
TEST_ASSERT(latin1 == expect);
}
}
// verify that surrogates are handled as expected.
{
const QString thumbsUpQstr{"\U0001F44D"};
Expand Down
8 changes: 7 additions & 1 deletion src/global/SendToUser.cpp
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Expand Up @@ -25,8 +25,14 @@ void registerSendToUser(Signal2Lifetime &lifetime, Signal2<QString>::Function ca

void sendToUser(const QString &str)
{
using namespace mmqt;
ABORT_IF_NOT_ON_MAIN_THREAD();
auto &fn = getSendToUser();
fn.invoke(str);
if (str.endsWith(QC_NEWLINE)) {
fn.invoke(str);
} else {
qWarning() << "sendToUser() missing a newline: " << str;
fn.invoke(str + QS_NEWLINE);
}
}
} // namespace global
2 changes: 1 addition & 1 deletion src/proxy/MudTelnet.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -461,7 +461,7 @@ void MudTelnet::virt_receiveGmcpMessage(const GmcpMessage &msg)
const auto result = optString.value_or("missing text");
qDebug() << "Failure" << action << "remote message" << id << result;
// Mume doesn't send anything, so we have to make our own message.
global::sendToUser(QString("Failure %1 remote message: %1").arg(action, result));
global::sendToUser(QString("Failure %1 remote message: %2\n").arg(action, result));
}
return;
}
Expand Down
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