diff options
Diffstat (limited to 'src/corelib/tools/qbitarray.cpp')
| -rw-r--r-- | src/corelib/tools/qbitarray.cpp | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/src/corelib/tools/qbitarray.cpp b/src/corelib/tools/qbitarray.cpp index 4e8e3c241e..f0b81cce66 100644 --- a/src/corelib/tools/qbitarray.cpp +++ b/src/corelib/tools/qbitarray.cpp @@ -1,7 +1,7 @@ /**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. -** Copyright (C) 2016 Intel Corporation. +** Copyright (C) 2019 Intel Corporation. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the QtCore module of the Qt Toolkit. @@ -132,12 +132,12 @@ QT_BEGIN_NAMESPACE * We overallocate the byte array by 1 byte. The first user bit is at * d.data()[1]. On the extra first byte, we store the difference between the * number of bits in the byte array (including this byte) and the number of - * bits in the bit array. Therefore, it's always a number between 8 and 15. + * bits in the bit array. Therefore, for a non-empty QBitArray, it's always a + * number between 8 and 15. For the empty one, d is the an empty QByteArray and + * *d.constData() is the QByteArray's terminating NUL (0) byte. * * This allows for fast calculation of the bit array size: * inline int size() const { return (d.size() << 3) - *d.constData(); } - * - * Note: for an array of zero size, *d.constData() is the QByteArray implicit NUL. */ /*! @@ -154,8 +154,8 @@ QBitArray::QBitArray(int size, bool value) uchar* c = reinterpret_cast<uchar*>(d.data()); memset(c + 1, value ? 0xff : 0, d.size() - 1); *c = d.size()*8 - size; - if (value && size && size % 8) - *(c+1+size/8) &= (1 << (size%8)) - 1; + if (value && size && size & 7) + *(c+1+size/8) &= (1 << (size & 7)) - 1; } /*! \fn int QBitArray::size() const @@ -227,8 +227,8 @@ void QBitArray::resize(int size) uchar* c = reinterpret_cast<uchar*>(d.data()); if (size > (s << 3)) memset(c + s, 0, d.size() - s); - else if ( size % 8) - *(c+1+size/8) &= (1 << (size%8)) - 1; + else if (size & 7) + *(c+1+size/8) &= (1 << (size & 7)) - 1; *c = d.size()*8 - size; } } @@ -326,6 +326,8 @@ void QBitArray::fill(bool value, int begin, int end) QBitArray QBitArray::fromBits(const char *data, qsizetype size) { QBitArray result; + if (size == 0) + return result; qsizetype nbytes = (size + 7) / 8; result.d = QByteArray(nbytes + 1, Qt::Uninitialized); @@ -334,7 +336,7 @@ QBitArray QBitArray::fromBits(const char *data, qsizetype size) // clear any unused bits from the last byte if (size & 7) - bits[nbytes] &= 0xffU >> (size & 7); + bits[nbytes] &= 0xffU >> (8 - (size & 7)); *bits = result.d.size() * 8 - size; return result; |