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CBOR: fix the UTF8-and-UTF16 detection 

This isn't a bug, it just removes dead code. The code to compare
US-ASCII to UTF-16 was never engaged because this conditional was wrong
and effectively catching everything. Fortunately, because that
comparison code is now wrong with the unit tests added to tst_QCborValue
in the past few commits.

Pick-to: 6.7
Change-Id: If1bf59ecbe014b569ba1fffd17c4ce184948e646
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
bb10
Thiago Macieira 2024-04-09 20:39:21 -07:00
parent 0533d1d544
commit af9f3c5da2
1 changed files with 17 additions and 41 deletions
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58
src/corelib/serialization/qcborvalue.cpp
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@ -1221,12 +1221,6 @@ static int compareElementRecursive(const QCborContainerPrivate *c1, const Elemen
const ByteData *b1 = c1 ? c1->byteData(e1) : nullptr;
const ByteData *b2 = c2 ? c2->byteData(e2) : nullptr;
if (b1 || b2) {
auto compareStrings = [mode](auto s1, auto s2) {
if (mode == Comparison::ForEquality)
return QtPrivate::equalStrings(s1, s2) ? 0 : 1;
return QtPrivate::compareStrings(s1, s2);
};
auto len1 = b1 ? b1->len : 0;
auto len2 = b2 ? b2->len : 0;
@ -1242,22 +1236,14 @@ static int compareElementRecursive(const QCborContainerPrivate *c1, const Elemen
Q_ASSERT(b2);
// Officially with CBOR, we sort first the string with the shortest
// UTF-8 length. The length of an ASCII string is the same as its UTF-8
// and UTF-16 ones, but the UTF-8 length of a string is bigger than the
// UTF-16 equivalent. Combinations are:
// 1) UTF-16 and UTF-16
// 2) UTF-16 and UTF-8 <=== this is the problem case
// 3) UTF-16 and US-ASCII
// 4) UTF-8 and UTF-8
// 5) UTF-8 and US-ASCII
// 6) US-ASCII and US-ASCII
if ((e1.flags & Element::StringIsUtf16) && (e2.flags & Element::StringIsUtf16)) {
// Case 1: both UTF-16
// UTF-8 length. Since US-ASCII is just a subset of UTF-8, its length
// is the UTF-8 length. But the UTF-16 length may not be directly
// comparable.
if ((e1.flags & Element::StringIsUtf16) && (e2.flags & Element::StringIsUtf16))
return compareStringsInUtf8(b1->asStringView(), b2->asStringView(), mode);
}
if (!(e1.flags & Element::StringIsUtf16) && !(e2.flags & Element::StringIsUtf16)) {
// Cases 4, 5 and 6: neither is UTF-16, so lengths are comparable too
// Neither is UTF-16, so lengths are comparable too
// (this case includes byte arrays too)
if (len1 == len2) {
if (mode == Comparison::ForEquality) {
@ -1269,29 +1255,19 @@ static int compareElementRecursive(const QCborContainerPrivate *c1, const Elemen
return len1 < len2 ? -1 : 1;
}
if (!(e1.flags & Element::StringIsAscii) || !(e2.flags & Element::StringIsAscii)) {
// Case 2: one of them is UTF-8 and the other is UTF-16, so lengths
// are NOT comparable. We need to convert to UTF-8 first...
// (we can't use QUtf8::compareUtf8 because we need to compare lengths)
auto string = [](const Element &e, const ByteData *b) -> QByteArray {
if (e.flags & Element::StringIsUtf16)
return b->asStringView().toUtf8();
return b->asByteArrayView(); // actually a QByteArray::fromRaw
};
// Only one is UTF-16
// (we can't use QUtf8::compareUtf8 because we need to compare lengths)
auto string = [](const Element &e, const ByteData *b) -> QByteArray {
if (e.flags & Element::StringIsUtf16)
return b->asStringView().toUtf8();
return b->asByteArrayView(); // actually a QByteArray::fromRaw
};
QByteArray s1 = string(e1, b1);
QByteArray s2 = string(e2, b2);
if (s1.size() == s2.size())
return memcmp(s1.constData(), s2.constData(), s1.size());
return s1.size() < s2.size() ? -1 : 1;
}
// Case 3 (UTF-16 and US-ASCII) remains, so lengths are comparable again
if (len1 != len2)
return len1 < len2 ? -1 : 1;
if (e1.flags & Element::StringIsUtf16)
return compareStrings(b1->asStringView(), b2->asLatin1());
return compareStrings(b1->asLatin1(), b2->asStringView());
QByteArray s1 = string(e1, b1);
QByteArray s2 = string(e2, b2);
if (s1.size() == s2.size())
return memcmp(s1.constData(), s2.constData(), s1.size());
return s1.size() < s2.size() ? -1 : 1;
}
return compareElementNoData(e1, e2);