1 files changed, 37 insertions, 20 deletions
diff --git a/src/corelib/tools/qarraydata.cpp b/src/corelib/tools/qarraydata.cpp
index ce6f1384977..bc486193492 100644
--- a/src/corelib/tools/qarraydata.cpp
+++ b/src/corelib/tools/qarraydata.cpp
@@ -153,17 +153,17 @@ QT_WARNING_PUSH
 QT_WARNING_DISABLE_GCC("-Wmissing-field-initializers")
 
 const QArrayData QArrayData::shared_null[2] = {
-    { Q_REFCOUNT_INITIALIZE_STATIC, 0, 0, 0, sizeof(QArrayData) }, // shared null
+    { Q_REFCOUNT_INITIALIZE_STATIC, QArrayData::StaticDataFlags, 0, 0, sizeof(QArrayData) }, // shared null
     /* zero initialized terminator */};
 
-static const QArrayData qt_array[3] = {
-    { Q_REFCOUNT_INITIALIZE_STATIC, 0, 0, 0, sizeof(QArrayData) }, // shared empty
-    { { Q_BASIC_ATOMIC_INITIALIZER(0) }, 0, 0, 0, sizeof(QArrayData) }, // unsharable empty
+static const QArrayData emptyNotNullShared[2] = {
+    { Q_REFCOUNT_INITIALIZE_STATIC, QArrayData::StaticDataFlags, 0, 0, sizeof(QArrayData) }, // shared empty
     /* zero initialized terminator */};
 
 QT_WARNING_POP
 
-static const QArrayData &qt_array_empty = qt_array[0];
+static const QArrayData &qt_array_empty = emptyNotNullShared[0];
+
 static inline size_t calculateBlockSize(size_t &capacity, size_t objectSize, size_t headerSize,
                                         uint options)
 {
@@ -179,6 +179,17 @@ static inline size_t calculateBlockSize(size_t &capacity, size_t objectSize, siz
     }
 }
 
+static QArrayData *allocateData(size_t allocSize, uint options)
+{
+    QArrayData *header = static_cast<QArrayData *>(::malloc(allocSize));
+    if (header) {
+        header->ref.atomic.storeRelaxed(1);
+        header->flags = options;
+        header->size = 0;
+    }
+    return header;
+}
+
 static QArrayData *reallocateData(QArrayData *header, size_t allocSize, uint options)
 {
     header = static_cast<QArrayData *>(::realloc(header, allocSize));
@@ -194,38 +205,43 @@ QArrayData *QArrayData::allocate(size_t objectSize, size_t alignment,
     Q_ASSERT(alignment >= alignof(QArrayData)
             && !(alignment & (alignment - 1)));
 
-    // Don't allocate empty headers
-    if (!(options & RawData) && !capacity)
+    if (capacity == 0)
+        // optimization for empty headers
         return const_cast<QArrayData *>(&qt_array_empty);
 
     size_t headerSize = sizeof(QArrayData);
 
-    // Allocate extra (alignment - alignof(QArrayData)) padding bytes so we
-    // can properly align the data array. This assumes malloc is able to
-    // provide appropriate alignment for the header -- as it should!
-    // Padding is skipped when allocating a header for RawData.
-    if (!(options & RawData))
-        headerSize += (alignment - alignof(QArrayData));
+    if (alignment > alignof(QArrayData)) {
+        // Allocate extra (alignment - Q_ALIGNOF(QArrayData)) padding bytes so we
+        // can properly align the data array. This assumes malloc is able to
+        // provide appropriate alignment for the header -- as it should!
+        headerSize += alignment - alignof(QArrayData);
+    }
 
     if (headerSize > size_t(MaxAllocSize))
         return nullptr;
 
     size_t allocSize = calculateBlockSize(capacity, objectSize, headerSize, options);
-    QArrayData *header = static_cast<QArrayData *>(::malloc(allocSize));
+    options |= ArrayOption(AllocatedDataType);
+    QArrayData *header = allocateData(allocSize, options);
     if (header) {
         quintptr data = (quintptr(header) + sizeof(QArrayData) + alignment - 1)
                 & ~(alignment - 1);
-
-        header->ref.atomic.storeRelaxed(1);
-        header->size = 0;
-        header->alloc = capacity;
-        header->flags = options;
         header->offset = data - quintptr(header);
+        header->alloc = capacity;
     }
 
     return header;
 }
 
+QArrayData *QArrayData::prepareRawData(ArrayOptions options) Q_DECL_NOTHROW
+{
+    QArrayData *header = allocateData(sizeof(QArrayData), (options & ~DataTypeBits) | RawDataType);
+    if (header)
+        header->alloc = 0;
+    return header;
+}
+
 QArrayData *QArrayData::reallocateUnaligned(QArrayData *data, size_t objectSize, size_t capacity,
                                             ArrayOptions options) noexcept
 {
@@ -233,9 +249,10 @@ QArrayData *QArrayData::reallocateUnaligned(QArrayData *data, size_t objectSize,
     Q_ASSERT(data->isMutable());
     Q_ASSERT(!data->ref.isShared());
 
+    options |= ArrayOption(AllocatedDataType);
     size_t headerSize = sizeof(QArrayData);
     size_t allocSize = calculateBlockSize(capacity, objectSize, headerSize, options);
-    QArrayData *header = static_cast<QArrayData *>(reallocateData(data, allocSize, options));
+    QArrayData *header = reallocateData(data, allocSize, options);
     if (header)
         header->alloc = capacity;
     return header;