X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/6cf2fb76fe35e84852cec2517703d9d5e068b4a8..530ecef01f7e33c2ec1b8b1ad8025484709bef1d:/src/common/zipstrm.cpp diff --git a/src/common/zipstrm.cpp b/src/common/zipstrm.cpp index a2e12cc38b..1358b48275 100644 --- a/src/common/zipstrm.cpp +++ b/src/common/zipstrm.cpp @@ -1,5 +1,5 @@ ///////////////////////////////////////////////////////////////////////////// -// Name: zipstrm.cpp +// Name: src/common/zipstrm.cpp // Purpose: Streams for Zip files // Author: Mike Wetherell // RCS-ID: $Id$ @@ -11,22 +11,21 @@ #include "wx/wxprec.h" #ifdef __BORLANDC__ - #pragma hdrstop + #pragma hdrstop #endif +#if wxUSE_ZLIB && wxUSE_STREAMS && wxUSE_ZIPSTREAM + #ifndef WX_PRECOMP - #include "wx/defs.h" + #include "wx/intl.h" + #include "wx/log.h" + #include "wx/utils.h" #endif -#if wxUSE_ZLIB && wxUSE_STREAMS && wxUSE_ZIPSTREAM - #include "wx/zipstrm.h" -#include "wx/log.h" -#include "wx/intl.h" #include "wx/datstrm.h" #include "wx/zstream.h" #include "wx/mstream.h" -#include "wx/utils.h" #include "wx/buffer.h" #include "wx/ptr_scpd.h" #include "wx/wfstream.h" @@ -117,7 +116,7 @@ static inline wxUint32 CrackUint32(const char *m) // static wxFileOffset QuietSeek(wxInputStream& stream, wxFileOffset pos) { -#ifdef __WXDEBUG__ +#if defined(__WXDEBUG__) && wxUSE_LOG wxLogLevel level = wxLog::GetLogLevel(); wxLog::SetLogLevel(wxLOG_Debug - 1); wxFileOffset result = stream.SeekI(pos); @@ -129,6 +128,69 @@ static wxFileOffset QuietSeek(wxInputStream& stream, wxFileOffset pos) } +///////////////////////////////////////////////////////////////////////////// +// Read a zip header + +class wxZipHeader +{ +public: + wxZipHeader(wxInputStream& stream, size_t size); + + inline wxUint8 Read8(); + inline wxUint16 Read16(); + inline wxUint32 Read32(); + + const char *GetData() const { return m_data; } + size_t GetSize() const { return m_size; } + operator bool() const { return m_ok; } + + size_t Seek(size_t pos) { m_pos = pos; return m_pos; } + size_t Skip(size_t size) { m_pos += size; return m_pos; } + + wxZipHeader& operator>>(wxUint8& n) { n = Read8(); return *this; } + wxZipHeader& operator>>(wxUint16& n) { n = Read16(); return *this; } + wxZipHeader& operator>>(wxUint32& n) { n = Read32(); return *this; } + +private: + char m_data[64]; + size_t m_size; + size_t m_pos; + bool m_ok; +}; + +wxZipHeader::wxZipHeader(wxInputStream& stream, size_t size) + : m_size(0), + m_pos(0), + m_ok(false) +{ + wxCHECK_RET(size <= sizeof(m_data), _T("buffer too small")); + m_size = stream.Read(m_data, size).LastRead(); + m_ok = m_size == size; +} + +wxUint8 wxZipHeader::Read8() +{ + wxASSERT(m_pos < m_size); + return *wx_reinterpret_cast(wxUint8*, m_data + m_pos++); +} + +wxUint16 wxZipHeader::Read16() +{ + wxASSERT(m_pos + 2 <= m_size); + wxUint16 n = *wx_reinterpret_cast(wxUint16*, m_data + m_pos); + m_pos += 2; + return wxUINT16_SWAP_ON_BE(n); +} + +wxUint32 wxZipHeader::Read32() +{ + wxASSERT(m_pos + 4 <= m_size); + wxUint32 n = *wx_reinterpret_cast(wxUint32*, m_data + m_pos); + m_pos += 4; + return wxUINT32_SWAP_ON_BE(n); +} + + ///////////////////////////////////////////////////////////////////////////// // Stored input stream // Trival decompressor for files which are 'stored' in the zip file. @@ -164,14 +226,13 @@ wxStoredInputStream::wxStoredInputStream(wxInputStream& stream) size_t wxStoredInputStream::OnSysRead(void *buffer, size_t size) { - size_t count = wxMin(size, wx_truncate_cast(size_t, m_len - m_pos)); + size_t count = wx_truncate_cast(size_t, + wxMin(size + wxFileOffset(0), m_len - m_pos + size_t(0))); count = m_parent_i_stream->Read(buffer, count).LastRead(); m_pos += count; - if (m_pos == m_len) - m_lasterror = wxSTREAM_EOF; - else if (!*m_parent_i_stream) - m_lasterror = wxSTREAM_READ_ERROR; + if (count < size) + m_lasterror = m_pos == m_len ? wxSTREAM_EOF : wxSTREAM_READ_ERROR; return count; } @@ -294,7 +355,8 @@ wxInputStream& wxTeeInputStream::Read(void *buffer, size_t size) size_t wxTeeInputStream::OnSysRead(void *buffer, size_t size) { size_t count = m_parent_i_stream->Read(buffer, size).LastRead(); - m_lasterror = m_parent_i_stream->GetLastError(); + if (count < size) + m_lasterror = m_parent_i_stream->GetLastError(); return count; } @@ -308,6 +370,7 @@ size_t wxTeeInputStream::GetData(char *buffer, size_t size) wxFAIL; // we've already returned data that's now being ungot m_end = len; } + m_parent_i_stream->Reset(); m_parent_i_stream->Ungetch(m_wback, m_wbacksize); free(m_wback); m_wback = NULL; @@ -483,6 +546,8 @@ private: size_t m_size; size_t m_capacity; int m_ref; + + wxSUPPRESS_GCC_PRIVATE_DTOR_WARNING(wxZipMemory) }; wxZipMemory *wxZipMemory::Unique(size_t size) @@ -552,20 +617,24 @@ public: wxZipWeakLinks *AddEntry(wxZipEntry *entry, wxFileOffset key); void RemoveEntry(wxFileOffset key) - { m_entries.erase((wx__OffsetZipEntryMap::key_type)key); } + { m_entries.erase(wx_truncate_cast(key_type, key)); } wxZipEntry *GetEntry(wxFileOffset key) const; bool IsEmpty() const { return m_entries.empty(); } private: ~wxZipWeakLinks() { wxASSERT(IsEmpty()); } + typedef wx__OffsetZipEntryMap::key_type key_type; + int m_ref; wx__OffsetZipEntryMap m_entries; + + wxSUPPRESS_GCC_PRIVATE_DTOR_WARNING(wxZipWeakLinks) }; wxZipWeakLinks *wxZipWeakLinks::AddEntry(wxZipEntry *entry, wxFileOffset key) { - m_entries[(wx__OffsetZipEntryMap::key_type)key] = entry; + m_entries[wx_truncate_cast(key_type, key)] = entry; m_ref++; return this; } @@ -573,7 +642,7 @@ wxZipWeakLinks *wxZipWeakLinks::AddEntry(wxZipEntry *entry, wxFileOffset key) wxZipEntry *wxZipWeakLinks::GetEntry(wxFileOffset key) const { wx__OffsetZipEntryMap::const_iterator it = - m_entries.find((wx__OffsetZipEntryMap::key_type)key); + m_entries.find(wx_truncate_cast(key_type, key)); return it != m_entries.end() ? it->second : NULL; } @@ -862,7 +931,9 @@ size_t wxZipEntry::ReadLocal(wxInputStream& stream, wxMBConv& conv) wxUint16 nameLen, extraLen; wxUint32 compressedSize, size, crc; - wxDataInputStream ds(stream); + wxZipHeader ds(stream, LOCAL_SIZE - 4); + if (!ds) + return 0; ds >> m_VersionNeeded >> m_Flags >> m_Method; SetDateTime(wxDateTime().SetFromDOS(ds.Read32())); @@ -878,11 +949,16 @@ size_t wxZipEntry::ReadLocal(wxInputStream& stream, wxMBConv& conv) m_Size = size; SetName(ReadString(stream, nameLen, conv), wxPATH_UNIX); + if (stream.LastRead() != nameLen + 0u) + return 0; if (extraLen || GetLocalExtraLen()) { Unique(m_LocalExtra, extraLen); - if (extraLen) + if (extraLen) { stream.Read(m_LocalExtra->GetData(), extraLen); + if (stream.LastRead() != extraLen + 0u) + return 0; + } } return LOCAL_SIZE + nameLen + extraLen; @@ -894,7 +970,7 @@ size_t wxZipEntry::WriteLocal(wxOutputStream& stream, wxMBConv& conv) const const wxWX2MBbuf name_buf = conv.cWX2MB(unixName); const char *name = name_buf; if (!name) name = ""; - wxUint16 nameLen = (wxUint16)strlen(name); + wxUint16 nameLen = wx_truncate_cast(wxUint16, strlen(name)); wxDataOutputStream ds(stream); @@ -902,11 +978,13 @@ size_t wxZipEntry::WriteLocal(wxOutputStream& stream, wxMBConv& conv) const ds.Write32(GetDateTime().GetAsDOS()); ds.Write32(m_Crc); - ds.Write32(m_CompressedSize != wxInvalidOffset ? (wxUint32)m_CompressedSize : 0); - ds.Write32(m_Size != wxInvalidOffset ? (wxUint32)m_Size : 0); + ds.Write32(m_CompressedSize != wxInvalidOffset ? + wx_truncate_cast(wxUint32, m_CompressedSize) : 0); + ds.Write32(m_Size != wxInvalidOffset ? + wx_truncate_cast(wxUint32, m_Size) : 0); ds << nameLen; - wxUint16 extraLen = (wxUint16)GetLocalExtraLen(); + wxUint16 extraLen = wx_truncate_cast(wxUint16, GetLocalExtraLen()); ds.Write16(extraLen); stream.Write(name, nameLen); @@ -920,7 +998,9 @@ size_t wxZipEntry::ReadCentral(wxInputStream& stream, wxMBConv& conv) { wxUint16 nameLen, extraLen, commentLen; - wxDataInputStream ds(stream); + wxZipHeader ds(stream, CENTRAL_SIZE - 4); + if (!ds) + return 0; ds >> m_VersionMadeBy >> m_SystemMadeBy; @@ -937,17 +1017,25 @@ size_t wxZipEntry::ReadCentral(wxInputStream& stream, wxMBConv& conv) SetOffset(ds.Read32()); SetName(ReadString(stream, nameLen, conv), wxPATH_UNIX); + if (stream.LastRead() != nameLen + 0u) + return 0; if (extraLen || GetExtraLen()) { Unique(m_Extra, extraLen); - if (extraLen) + if (extraLen) { stream.Read(m_Extra->GetData(), extraLen); + if (stream.LastRead() != extraLen + 0u) + return 0; + } } - if (commentLen) + if (commentLen) { m_Comment = ReadString(stream, commentLen, conv); - else + if (stream.LastRead() != commentLen + 0u) + return 0; + } else { m_Comment.clear(); + } return CENTRAL_SIZE + nameLen + extraLen + commentLen; } @@ -958,31 +1046,31 @@ size_t wxZipEntry::WriteCentral(wxOutputStream& stream, wxMBConv& conv) const const wxWX2MBbuf name_buf = conv.cWX2MB(unixName); const char *name = name_buf; if (!name) name = ""; - wxUint16 nameLen = (wxUint16)strlen(name); + wxUint16 nameLen = wx_truncate_cast(wxUint16, strlen(name)); const wxWX2MBbuf comment_buf = conv.cWX2MB(m_Comment); const char *comment = comment_buf; if (!comment) comment = ""; - wxUint16 commentLen = (wxUint16)strlen(comment); + wxUint16 commentLen = wx_truncate_cast(wxUint16, strlen(comment)); - wxUint16 extraLen = (wxUint16)GetExtraLen(); + wxUint16 extraLen = wx_truncate_cast(wxUint16, GetExtraLen()); wxDataOutputStream ds(stream); ds << CENTRAL_MAGIC << m_VersionMadeBy << m_SystemMadeBy; - ds.Write16((wxUint16)GetVersionNeeded()); - ds.Write16((wxUint16)GetFlags()); - ds.Write16((wxUint16)GetMethod()); + ds.Write16(wx_truncate_cast(wxUint16, GetVersionNeeded())); + ds.Write16(wx_truncate_cast(wxUint16, GetFlags())); + ds.Write16(wx_truncate_cast(wxUint16, GetMethod())); ds.Write32(GetDateTime().GetAsDOS()); ds.Write32(GetCrc()); - ds.Write32((wxUint32)GetCompressedSize()); - ds.Write32((wxUint32)GetSize()); + ds.Write32(wx_truncate_cast(wxUint32, GetCompressedSize())); + ds.Write32(wx_truncate_cast(wxUint32, GetSize())); ds.Write16(nameLen); ds.Write16(extraLen); ds << commentLen << m_DiskStart << m_InternalAttributes - << m_ExternalAttributes << (wxUint32)GetOffset(); + << m_ExternalAttributes << wx_truncate_cast(wxUint32, GetOffset()); stream.Write(name, nameLen); if (extraLen) @@ -999,7 +1087,9 @@ size_t wxZipEntry::WriteCentral(wxOutputStream& stream, wxMBConv& conv) const // size_t wxZipEntry::ReadDescriptor(wxInputStream& stream) { - wxDataInputStream ds(stream); + wxZipHeader ds(stream, SUMS_SIZE); + if (!ds) + return 0; m_Crc = ds.Read32(); m_CompressedSize = ds.Read32(); @@ -1008,23 +1098,24 @@ size_t wxZipEntry::ReadDescriptor(wxInputStream& stream) // if 1st value is the signature then this is probably an info-zip record if (m_Crc == SUMS_MAGIC) { - char buf[8]; - stream.Read(buf, sizeof(buf)); - wxUint32 u1 = CrackUint32(buf); - wxUint32 u2 = CrackUint32(buf + 4); + wxZipHeader buf(stream, 8); + wxUint32 u1 = buf.GetSize() >= 4 ? buf.Read32() : (wxUint32)LOCAL_MAGIC; + wxUint32 u2 = buf.GetSize() == 8 ? buf.Read32() : 0; // look for the signature of the following record to decide which if ((u1 == LOCAL_MAGIC || u1 == CENTRAL_MAGIC) && (u2 != LOCAL_MAGIC && u2 != CENTRAL_MAGIC)) { // it's a pkzip style record after all! - stream.Ungetch(buf, sizeof(buf)); + if (buf.GetSize() > 0) + stream.Ungetch(buf.GetData(), buf.GetSize()); } else { // it's an info-zip record as expected - stream.Ungetch(buf + 4, sizeof(buf) - 4); - m_Crc = (wxUint32)m_CompressedSize; + if (buf.GetSize() > 4) + stream.Ungetch(buf.GetData() + 4, buf.GetSize() - 4); + m_Crc = wx_truncate_cast(wxUint32, m_CompressedSize); m_CompressedSize = m_Size; m_Size = u1; return SUMS_SIZE + 4; @@ -1044,8 +1135,8 @@ size_t wxZipEntry::WriteDescriptor(wxOutputStream& stream, wxUint32 crc, wxDataOutputStream ds(stream); ds.Write32(crc); - ds.Write32((wxUint32)compressedSize); - ds.Write32((wxUint32)size); + ds.Write32(wx_truncate_cast(wxUint32, compressedSize)); + ds.Write32(wx_truncate_cast(wxUint32, size)); return SUMS_SIZE; } @@ -1067,13 +1158,20 @@ public: wxFileOffset GetOffset() const { return m_Offset; } wxString GetComment() const { return m_Comment; } - void SetDiskNumber(int num) { m_DiskNumber = (wxUint16)num; } - void SetStartDisk(int num) { m_StartDisk = (wxUint16)num; } - void SetEntriesHere(int num) { m_EntriesHere = (wxUint16)num; } - void SetTotalEntries(int num) { m_TotalEntries = (wxUint16)num; } - void SetSize(wxFileOffset size) { m_Size = (wxUint32)size; } - void SetOffset(wxFileOffset offset) { m_Offset = (wxUint32)offset; } - void SetComment(const wxString& comment) { m_Comment = comment; } + void SetDiskNumber(int num) + { m_DiskNumber = wx_truncate_cast(wxUint16, num); } + void SetStartDisk(int num) + { m_StartDisk = wx_truncate_cast(wxUint16, num); } + void SetEntriesHere(int num) + { m_EntriesHere = wx_truncate_cast(wxUint16, num); } + void SetTotalEntries(int num) + { m_TotalEntries = wx_truncate_cast(wxUint16, num); } + void SetSize(wxFileOffset size) + { m_Size = wx_truncate_cast(wxUint32, size); } + void SetOffset(wxFileOffset offset) + { m_Offset = wx_truncate_cast(wxUint32, offset); } + void SetComment(const wxString& comment) + { m_Comment = comment; } bool Read(wxInputStream& stream, wxMBConv& conv); bool Write(wxOutputStream& stream, wxMBConv& conv) const; @@ -1117,23 +1215,26 @@ bool wxZipEndRec::Write(wxOutputStream& stream, wxMBConv& conv) const bool wxZipEndRec::Read(wxInputStream& stream, wxMBConv& conv) { - wxDataInputStream ds(stream); + wxZipHeader ds(stream, END_SIZE - 4); + if (!ds) + return false; + wxUint16 commentLen; ds >> m_DiskNumber >> m_StartDisk >> m_EntriesHere >> m_TotalEntries >> m_Size >> m_Offset >> commentLen; - if (commentLen) + if (commentLen) { m_Comment = ReadString(stream, commentLen, conv); + if (stream.LastRead() != commentLen + 0u) + return false; + } - if (stream.IsOk()) - if (m_DiskNumber == 0 && m_StartDisk == 0 && - m_EntriesHere == m_TotalEntries) - return true; - else - wxLogError(_("unsupported zip archive")); + if (m_DiskNumber != 0 || m_StartDisk != 0 || + m_EntriesHere != m_TotalEntries) + wxLogWarning(_("assuming this is a multi-part zip concatenated")); - return false; + return true; } @@ -1158,6 +1259,8 @@ private: int m_ref; wxZipOutputStream *m_stream; + + wxSUPPRESS_GCC_PRIVATE_DTOR_WARNING(wxZipStreamLink) }; @@ -1301,9 +1404,7 @@ bool wxZipInputStream::LoadEndRecord() else { wxLogNull nolog; wxFileOffset pos = m_parent_i_stream->TellI(); - // FIXME - //if (pos != wxInvalidOffset) - if (pos >= 0 && pos <= LONG_MAX) + if (pos != wxInvalidOffset) m_offsetAdjustment = m_position = pos; return true; } @@ -1313,14 +1414,8 @@ bool wxZipInputStream::LoadEndRecord() // Read in the end record wxFileOffset endPos = m_parent_i_stream->TellI() - 4; - if (!endrec.Read(*m_parent_i_stream, GetConv())) { - if (!*m_parent_i_stream) { - m_lasterror = wxSTREAM_READ_ERROR; - return false; - } - // TODO: try this out - wxLogWarning(_("assuming this is a multi-part zip concatenated")); - } + if (!endrec.Read(*m_parent_i_stream, GetConv())) + return false; m_TotalEntries = endrec.GetTotalEntries(); m_Comment = endrec.GetComment(); @@ -1384,7 +1479,8 @@ bool wxZipInputStream::FindEndRecord() wxFileOffset minpos = wxMax(pos - 65535L, 0); while (pos > minpos) { - size_t len = (size_t)(pos - wxMax(pos - (BUFSIZE - 3), minpos)); + size_t len = wx_truncate_cast(size_t, + pos - wxMax(pos - (BUFSIZE - 3), minpos)); memcpy(buf.data() + len, buf, 3); pos -= len; @@ -1438,12 +1534,13 @@ wxStreamError wxZipInputStream::ReadCentral() if (QuietSeek(*m_parent_i_stream, m_position + 4) == wxInvalidOffset) return wxSTREAM_READ_ERROR; - m_position += m_entry.ReadCentral(*m_parent_i_stream, GetConv()); - if (m_parent_i_stream->GetLastError() == wxSTREAM_READ_ERROR) { + size_t size = m_entry.ReadCentral(*m_parent_i_stream, GetConv()); + if (!size) { m_signature = 0; return wxSTREAM_READ_ERROR; } + m_position += size; m_signature = ReadSignature(); if (m_offsetAdjustment) @@ -1472,9 +1569,10 @@ wxStreamError wxZipInputStream::ReadLocal(bool readEndRec /*=false*/) if (m_weaklinks->IsEmpty() && m_streamlink == NULL) return wxSTREAM_EOF; - m_position += m_entry.ReadCentral(*m_parent_i_stream, GetConv()); + size_t size = m_entry.ReadCentral(*m_parent_i_stream, GetConv()); + m_position += size; m_signature = 0; - if (m_parent_i_stream->GetLastError() == wxSTREAM_READ_ERROR) + if (!size) return wxSTREAM_READ_ERROR; wxZipEntry *entry = m_weaklinks->GetEntry(m_entry.GetOffset()); @@ -1518,7 +1616,7 @@ wxStreamError wxZipInputStream::ReadLocal(bool readEndRec /*=false*/) m_entry.SetOffset(m_position); m_entry.SetKey(m_position); - if (m_parent_i_stream->GetLastError() == wxSTREAM_READ_ERROR) { + if (!m_headerSize) { return wxSTREAM_READ_ERROR; } else { m_TotalEntries++; @@ -1548,7 +1646,8 @@ bool wxZipInputStream::DoOpen(wxZipEntry *entry, bool raw) return false; if (m_lasterror == wxSTREAM_READ_ERROR) return false; - wxCHECK(!IsOpened(), false); + if (IsOpened()) + CloseEntry(); m_raw = raw; @@ -1576,7 +1675,7 @@ bool wxZipInputStream::DoOpen(wxZipEntry *entry, bool raw) if (m_parentSeekable || AtHeader()) { m_headerSize = m_entry.ReadLocal(*m_parent_i_stream, GetConv()); - if (m_parentSeekable) { + if (m_headerSize && m_parentSeekable) { wxZipEntry *ref = m_weaklinks->GetEntry(m_entry.GetKey()); if (ref) { Copy(ref->m_LocalExtra, m_entry.m_LocalExtra); @@ -1590,7 +1689,8 @@ bool wxZipInputStream::DoOpen(wxZipEntry *entry, bool raw) } } - m_lasterror = m_parent_i_stream->GetLastError(); + if (m_headerSize) + m_lasterror = wxSTREAM_NO_ERROR; return IsOk(); } @@ -1709,7 +1809,8 @@ size_t wxZipInputStream::OnSysRead(void *buffer, size_t size) size_t count = m_decomp->Read(buffer, size).LastRead(); if (!m_raw) m_crcAccumulator = crc32(m_crcAccumulator, (Byte*)buffer, count); - m_lasterror = m_decomp->GetLastError(); + if (count < size) + m_lasterror = m_decomp->GetLastError(); if (Eof()) { if ((m_entry.GetFlags() & wxZIP_SUMS_FOLLOW) != 0) { @@ -1727,16 +1828,14 @@ size_t wxZipInputStream::OnSysRead(void *buffer, size_t size) if (!m_raw) { m_lasterror = wxSTREAM_READ_ERROR; - if (m_parent_i_stream->IsOk()) { - if (m_entry.GetSize() != TellI()) - wxLogError(_("reading zip stream (entry %s): bad length"), - m_entry.GetName().c_str()); - else if (m_crcAccumulator != m_entry.GetCrc()) - wxLogError(_("reading zip stream (entry %s): bad crc"), - m_entry.GetName().c_str()); - else - m_lasterror = wxSTREAM_EOF; - } + if (m_entry.GetSize() != TellI()) + wxLogError(_("reading zip stream (entry %s): bad length"), + m_entry.GetName().c_str()); + else if (m_crcAccumulator != m_entry.GetCrc()) + wxLogError(_("reading zip stream (entry %s): bad crc"), + m_entry.GetName().c_str()); + else + m_lasterror = wxSTREAM_EOF; } } @@ -1775,31 +1874,30 @@ wxFileOffset wxZipInputStream::OnSysSeek(wxFileOffset seek, wxSeekMode mode) default : nextpos = pos; break; /* just to fool compiler, never happens */ } - size_t toskip wxDUMMY_INITIALIZE(0); + wxFileOffset toskip wxDUMMY_INITIALIZE(0); if ( nextpos >= pos ) { - toskip = (size_t)(nextpos - pos); + toskip = nextpos - pos; } else { wxZipEntry current(m_entry); - CloseEntry(); if (!OpenEntry(current)) { m_lasterror = wxSTREAM_READ_ERROR; return pos; } - toskip = (size_t)nextpos; + toskip = nextpos; } if ( toskip > 0 ) { - const size_t BUFSIZE = 4096; + const int BUFSIZE = 4096; size_t sz; char buffer[BUFSIZE]; while ( toskip > 0 ) { - sz = wxMin(toskip, BUFSIZE); + sz = wx_truncate_cast(size_t, wxMin(toskip, BUFSIZE)); Read(buffer, sz); toskip -= sz; }