office-gobmx/include/systools/win32/oleauto.hxx
Mike Kaganski a2c3ef6d81 Move BSTR wrapper to systools, and fix some wrong BSTR uses
BSTR is documented [1] to be prefixed by a 32-bit integer specifying
its length *in bytes* (not characters), so passing wchar_t* as BSTR
is wrong, and the length member of rtl_uString can't substitute the
proper BSTR length, since rtl_uString::length specifies length in
characters. Any code taking BSTR and using SysStringLen to get its
length would only get half of the passed OUString data.

In dbaccess/source/ui/dlg/adodatalinks.cxx, the abovementioned
error was implemented. OTOH, OLEVariant::getByteSequence() in
connectivity/source/drivers/ado/Aolevariant.cxx passed BSTR from
tagVARIANT to ctor of OLEString, which resulted in the BSTR being
freed in both dtors of OLEString and OLEVariant (the latter calls
VariantClear, which itself clears string when vtfield is VT_BSTR).

[1] https://docs.microsoft.com/en-us/previous-versions/windows/desktop/automat/bstr

Change-Id: Iedbd62b20133644258af3660616add7b63cac258
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/131950
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
2022-03-22 22:23:56 +01:00

84 lines
2.4 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#pragma once
#include <cassert>
#include <string_view>
#include <utility>
#include <prewin.h>
#include <oleauto.h>
#include <postwin.h>
#include <o3tl/char16_t2wchar_t.hxx>
namespace sal::systools
{
// BSTR safe wrapper
class BStr
{
public:
BStr() = default;
BStr(std::u16string_view sv)
: m_Str(::SysAllocStringLen(o3tl::toW(sv.data()), sv.length()))
{
}
BStr(const BStr& src)
: BStr(std::u16string_view(src))
{
}
BStr(BStr&& src)
: m_Str(std::exchange(src.m_Str, nullptr))
{
}
~BStr() { ::SysFreeString(m_Str); }
BStr& operator=(std::u16string_view sv)
{
::SysFreeString(
std::exchange(m_Str, ::SysAllocStringLen(o3tl::toW(sv.data()), sv.length())));
return *this;
}
BStr& operator=(const BStr& src)
{
if (&src != this)
operator=(std::u16string_view(src));
return *this;
}
BStr& operator=(BStr&& src)
{
::SysFreeString(std::exchange(m_Str, std::exchange(src.m_Str, nullptr)));
return *this;
}
operator std::u16string_view() const { return { o3tl::toU(m_Str), length() }; }
operator BSTR() const { return m_Str; }
BSTR* operator&()
{
assert(!m_Str);
return &m_Str;
}
UINT length() const { return ::SysStringLen(m_Str); }
private:
BSTR m_Str = nullptr;
};
} // sal::systools
/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */