1 files changed, 35 insertions, 14 deletions
diff --git a/src/corelib/tools/qarraydata.cpp b/src/corelib/tools/qarraydata.cpp
index 5452fddaa89..37d6dea35f9 100644
--- a/src/corelib/tools/qarraydata.cpp
+++ b/src/corelib/tools/qarraydata.cpp
@@ -2,6 +2,7 @@
 // Copyright (C) 2016 Intel Corporation.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
+#include <QtCore/qalloc.h>
 #include <QtCore/qarraydata.h>
 #include <QtCore/private/qnumeric_p.h>
 #include <QtCore/private/qtools_p.h>
@@ -101,12 +102,34 @@ qCalculateGrowingBlockSize(qsizetype elementCount, qsizetype elementSize, qsizet
     } else {
         bytes = qsizetype(morebytes);
     }
+    size_t fittedBytes = QtPrivate::expectedAllocSize(bytes, alignof(std::max_align_t));
+    if (fittedBytes != 0)
+        bytes = fittedBytes;
 
     result.elementCount = (bytes - headerSize) / elementSize;
     result.size = result.elementCount * elementSize + headerSize;
     return result;
 }
 
+using QtPrivate::AlignedQArrayData;
+
+static qsizetype calculateHeaderSize(qsizetype alignment)
+{
+    qsizetype headerSize = sizeof(AlignedQArrayData);
+    const qsizetype headerAlignment = alignof(AlignedQArrayData);
+
+    if (alignment > headerAlignment) {
+        // Allocate extra (alignment - Q_ALIGNOF(AlignedQArrayData)) 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!
+        // Effectively, we allocate one QTypedArrayData<T>::AlignmentDummy.
+        headerSize += alignment - headerAlignment;
+    }
+    Q_ASSERT(headerSize > 0);
+
+    return headerSize;
+}
+
 /*
     Calculate the byte size for a block of \a capacity objects of size \a
     objectSize, with a header of size \a headerSize. If the \a option is
@@ -140,7 +163,6 @@ struct AllocationResult {
     QArrayData *header;
 };
 }
-using QtPrivate::AlignedQArrayData;
 
 static inline AllocationResult
 allocateHelper(qsizetype objectSize, qsizetype alignment, qsizetype capacity,
@@ -149,16 +171,7 @@ allocateHelper(qsizetype objectSize, qsizetype alignment, qsizetype capacity,
     if (capacity == 0)
         return {};
 
-    qsizetype headerSize = sizeof(AlignedQArrayData);
-    const qsizetype headerAlignment = alignof(AlignedQArrayData);
-
-    if (alignment > headerAlignment) {
-        // Allocate extra (alignment - Q_ALIGNOF(AlignedQArrayData)) 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!
-        // Effectively, we allocate one QTypedArrayData<T>::AlignmentDummy.
-        headerSize += alignment - headerAlignment;
-    }
+    const qsizetype headerSize = calculateHeaderSize(alignment);
     Q_ASSERT(headerSize > 0);
 
     auto blockSize = calculateBlockSize(capacity, objectSize, headerSize, option);
@@ -248,10 +261,18 @@ void QArrayData::deallocate(QArrayData *data, qsizetype objectSize,
     // Alignment is a power of two
     Q_ASSERT(alignment >= qsizetype(alignof(QArrayData))
             && !(alignment & (alignment - 1)));
-    Q_UNUSED(objectSize);
-    Q_UNUSED(alignment);
 
-    ::free(data);
+    const qsizetype capacity = data->alloc;
+    const qsizetype headerSize = calculateHeaderSize(alignment);
+    Q_ASSERT(headerSize > 0);
+    const auto blockSize = calculateBlockSize(capacity, objectSize,
+                                              headerSize, QArrayData::KeepSize);
+    const qsizetype allocSize = blockSize.size;
+
+    if (Q_LIKELY(allocSize > 0))
+        QtPrivate::sizedFree(data, size_t(allocSize));
+    else // something went wrong, fallback to slow free()
+        free(data);
 }
 
 QT_END_NAMESPACE