QCborStreamReader: remove the lambdas from decodeStringFromCbor()

One was only called once. For the other, one of the calls wasn't
necessary.

Pick-to: 5.15 6.0
Change-Id: I7b9b97ae9b32412abdc6fffd16454eec59d72b8a
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

1 files changed, 32 insertions, 43 deletions

diff --git a/src/corelib/serialization/qcborvalue.cpp b/src/corelib/serialization/qcborvalue.cpp
index f27ef94b4a..d9358a6bf6 100644
--- a/src/corelib/serialization/qcborvalue.cpp
+++ b/src/corelib/serialization/qcborvalue.cpp
@@ -1560,9 +1560,24 @@ extern QCborStreamReader::StringResultCode qt_cbor_append_string_chunk(QCborStre
 
 void QCborContainerPrivate::decodeStringFromCbor(QCborStreamReader &reader)
 {
-    // The use of size_t means none of the operations here can overflow because
-    // all inputs are less than half SIZE_MAX.
-    auto addByteData_local = [this](size_t len) -> qint64 {
+    if (reader.lastError() != QCborError::NoError)
+        return;
+
+    qsizetype rawlen = reader.currentStringChunkSize();
+    QByteArray::size_type len = rawlen;
+    if (rawlen < 0)
+        return;                     // error
+    if (len != rawlen) {
+        // truncation
+        setErrorInReader(reader, { QCborError::DataTooLarge });
+        return;
+    }
+
+    Element e = {};
+    e.type = (reader.isByteArray() ? QCborValue::ByteArray : QCborValue::String);
+    if (len || !reader.isLengthKnown()) {
+        // The use of size_t means none of the operations here can overflow because
+        // all inputs are less than half SIZE_MAX.
         constexpr size_t EstimatedOverhead = 16;
         constexpr size_t MaxMemoryIncrement = 16384;
         size_t offset = data.size();
@@ -1570,12 +1585,15 @@ void QCborContainerPrivate::decodeStringFromCbor(QCborStreamReader &reader)
         // add space for aligned ByteData (this can't overflow)
         offset += sizeof(QtCbor::ByteData) + alignof(QtCbor::ByteData);
         offset &= ~(alignof(QtCbor::ByteData) - 1);
-        if (offset > size_t(MaxByteArraySize))
-            return -1;
+        if (offset > size_t(MaxByteArraySize)) {
+            // overflow
+            setErrorInReader(reader, { QCborError::DataTooLarge });
+            return;
+        }
 
         // and calculate the size we want to have
         size_t newCapacity = offset + len;          // can't overflow
-        if (len > MaxMemoryIncrement - EstimatedOverhead) {
+        if (size_t(len) > MaxMemoryIncrement - EstimatedOverhead) {
             // there's a non-zero chance that we won't need this memory at all,
             // so capa how much we allocate
             newCapacity = offset + MaxMemoryIncrement - EstimatedOverhead;
@@ -1587,38 +1605,8 @@ void QCborContainerPrivate::decodeStringFromCbor(QCborStreamReader &reader)
         if (newCapacity > size_t(data.capacity()))
             data.reserve(newCapacity);
         data.resize(offset + sizeof(QtCbor::ByteData));
-        return offset;
-    };
-    auto dataPtr = [this]() {
-        // Null happens when we're reading zero bytes.
-        Q_ASSERT(data.isNull() || data.isDetached());
-        return const_cast<char *>(data.constData());
-    };
-
-    Element e = {};
-    e.type = (reader.isByteArray() ? QCborValue::ByteArray : QCborValue::String);
-    if (reader.lastError() != QCborError::NoError)
-        return;
-
-    qsizetype rawlen = reader.currentStringChunkSize();
-    QByteArray::size_type len = rawlen;
-    if (rawlen < 0)
-        return;                     // error
-    if (len != rawlen) {
-        // truncation
-        setErrorInReader(reader, { QCborError::DataTooLarge });
-        return;
-    }
-
-    // allocate space, but only if there will be data
-    if (len != 0 || !reader.isLengthKnown()) {
+        e.value = offset;
         e.flags = Element::HasByteData;
-        e.value = addByteData_local(len);
-        if (e.value < 0) {
-            // overflow
-            setErrorInReader(reader, { QCborError::DataTooLarge });
-            return;
-        }
     }
 
     // read chunks
@@ -1627,7 +1615,7 @@ void QCborContainerPrivate::decodeStringFromCbor(QCborStreamReader &reader)
     while (status == QCborStreamReader::Ok) {
         if (e.type == QCborValue::String && len) {
             // verify UTF-8 string validity
-            auto utf8result = QUtf8::isValidUtf8(QByteArrayView(dataPtr(), data.size()).last(len));
+            auto utf8result = QUtf8::isValidUtf8(QByteArrayView(data).last(len));
             if (!utf8result.isValidUtf8) {
                 status = QCborStreamReader::Error;
                 setErrorInReader(reader, { QCborError::InvalidUtf8String });
@@ -1648,8 +1636,10 @@ void QCborContainerPrivate::decodeStringFromCbor(QCborStreamReader &reader)
     }
 
     // update size
-    if (status == QCborStreamReader::EndOfString) {
-        auto b = new (dataPtr() + e.value) ByteData;
+    if (status == QCborStreamReader::EndOfString && e.flags & Element::HasByteData) {
+        Q_ASSERT(data.isDetached());
+        const char *ptr = data.constData() + e.value;
+        auto b = new (const_cast<char *>(ptr)) ByteData;
         b->len = data.size() - e.value - int(sizeof(*b));
         usedData += b->len;
 
@@ -1670,10 +1660,9 @@ void QCborContainerPrivate::decodeStringFromCbor(QCborStreamReader &reader)
 
     if (status == QCborStreamReader::Error) {
         data.truncate(e.value);
-        return;
+    } else {
+        elements.append(e);
     }
-
-    elements.append(e);
 }
 
 void QCborContainerPrivate::decodeValueFromCbor(QCborStreamReader &reader, int remainingRecursionDepth)