fixing overrelease and out-of-bounds write, fixes #13725

[wxWidgets.git] / src / common / stream.cpp

diff --git a/src/common/stream.cpp b/src/common/stream.cpp
index 90833f4c916c0f06858e377e7beef28fbbf32bb3..f7cd2ea2c58db63aa52248adc2857100f501c1e5 100644 (file)
--- a/src/common/stream.cpp
+++ b/src/common/stream.cpp
@@ -7,7 +7,7 @@
 // Created:     11/07/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Guilhem Lavaux
 // Created:     11/07/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Guilhem Lavaux

-// Licence:     wxWidgets licence
+// Licence:     wxWindows licence

 /////////////////////////////////////////////////////////////////////////////
 
 // ============================================================================
 /////////////////////////////////////////////////////////////////////////////
 
 // ============================================================================


@@ -18,28 +18,25 @@
 // headers
 // ----------------------------------------------------------------------------
 
 // headers
 // ----------------------------------------------------------------------------
 

-#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
-    #pragma implementation "stream.h"
-#endif
-

 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__

-  #pragma hdrstop
+    #pragma hdrstop

 #endif
 
 #endif
 

+#if wxUSE_STREAMS
+
+#include "wx/stream.h"
+

 #ifndef WX_PRECOMP
 #ifndef WX_PRECOMP

-  #include "wx/defs.h"
+    #include "wx/log.h"

 #endif
 
 #endif
 

-#if wxUSE_STREAMS
-

 #include <ctype.h>
 #include <ctype.h>

-#include "wx/stream.h"

 #include "wx/datstrm.h"
 #include "wx/textfile.h"
 #include "wx/datstrm.h"
 #include "wx/textfile.h"

-#include "wx/log.h"
+#include "wx/scopeguard.h"

 
 // ----------------------------------------------------------------------------
 // constants
 
 // ----------------------------------------------------------------------------
 // constants


@@ -67,37 +64,36 @@ void wxStreamBuffer::InitBuffer()
     m_buffer_start =
     m_buffer_end =
     m_buffer_pos = NULL;
     m_buffer_start =
     m_buffer_end =
     m_buffer_pos = NULL;

-    m_buffer_size = 0;

 
     // if we are going to allocate the buffer, we should free it later as well
 
     // if we are going to allocate the buffer, we should free it later as well

-    m_destroybuf = TRUE;
+    m_destroybuf = true;

 }
 
 void wxStreamBuffer::Init()
 {
     InitBuffer();
 
 }
 
 void wxStreamBuffer::Init()
 {
     InitBuffer();
 

-    m_fixed = TRUE;
+    m_fixed = true;

 }
 
 }
 

-wxStreamBuffer::wxStreamBuffer(BufMode mode)
+void wxStreamBuffer::InitWithStream(wxStreamBase& stream, BufMode mode)

 {
     Init();
 
 {
     Init();
 

-    m_stream = NULL;
+    m_stream = &stream;

     m_mode = mode;
 
     m_mode = mode;
 

-    m_flushable = FALSE;
+    m_flushable = true;

 }
 
 }
 

-wxStreamBuffer::wxStreamBuffer(wxStreamBase& stream, BufMode mode)
+wxStreamBuffer::wxStreamBuffer(BufMode mode)

 {
     Init();
 
 {
     Init();
 

-    m_stream = &stream;
+    m_stream = NULL;

     m_mode = mode;
 
     m_mode = mode;
 

-    m_flushable = TRUE;
+    m_flushable = false;

 }
 
 wxStreamBuffer::wxStreamBuffer(const wxStreamBuffer& buffer)
 }
 
 wxStreamBuffer::wxStreamBuffer(const wxStreamBuffer& buffer)


@@ -105,23 +101,25 @@ wxStreamBuffer::wxStreamBuffer(const wxStreamBuffer& buffer)
     // doing this has big chances to lead to a crash when the source buffer is
     // destroyed (otherwise assume the caller knows what he does)
     wxASSERT_MSG( !buffer.m_destroybuf,
     // doing this has big chances to lead to a crash when the source buffer is
     // destroyed (otherwise assume the caller knows what he does)
     wxASSERT_MSG( !buffer.m_destroybuf,

-                  _T("it's a bad idea to copy this buffer") );
+                  wxT("it's a bad idea to copy this buffer") );

 
     m_buffer_start = buffer.m_buffer_start;
     m_buffer_end = buffer.m_buffer_end;
     m_buffer_pos = buffer.m_buffer_pos;
 
     m_buffer_start = buffer.m_buffer_start;
     m_buffer_end = buffer.m_buffer_end;
     m_buffer_pos = buffer.m_buffer_pos;

-    m_buffer_size = buffer.m_buffer_size;

     m_fixed = buffer.m_fixed;
     m_flushable = buffer.m_flushable;
     m_stream = buffer.m_stream;
     m_mode = buffer.m_mode;
     m_fixed = buffer.m_fixed;
     m_flushable = buffer.m_flushable;
     m_stream = buffer.m_stream;
     m_mode = buffer.m_mode;

-    m_destroybuf = FALSE;
+    m_destroybuf = false;

 }
 
 void wxStreamBuffer::FreeBuffer()
 {
     if ( m_destroybuf )
 }
 
 void wxStreamBuffer::FreeBuffer()
 {
     if ( m_destroybuf )

+    {

         free(m_buffer_start);
         free(m_buffer_start);

+        m_buffer_start = NULL;
+    }

 }
 
 wxStreamBuffer::~wxStreamBuffer()
 }
 
 wxStreamBuffer::~wxStreamBuffer()


@@ -157,8 +155,6 @@ void wxStreamBuffer::SetBufferIO(void *start,
     m_buffer_start = (char *)start;
     m_buffer_end   = m_buffer_start + len;
 
     m_buffer_start = (char *)start;
     m_buffer_end   = m_buffer_start + len;
 

-    m_buffer_size = len;
-

     // if we own it, we free it
     m_destroybuf = takeOwnership;
 
     // if we own it, we free it
     m_destroybuf = takeOwnership;
 


@@ -167,15 +163,15 @@ void wxStreamBuffer::SetBufferIO(void *start,
 
 void wxStreamBuffer::SetBufferIO(size_t bufsize)
 {
 
 void wxStreamBuffer::SetBufferIO(size_t bufsize)
 {

-    // start by freeing the old buffer
-    FreeBuffer();
-

     if ( bufsize )
     {
     if ( bufsize )
     {

-        SetBufferIO(malloc(bufsize), bufsize, TRUE /* take ownership */);
+        // this will free the old buffer and allocate the new one
+        SetBufferIO(malloc(bufsize), bufsize, true /* take ownership */);

     }
     else // no buffer size => no buffer
     {
     }
     else // no buffer size => no buffer
     {

+        // still free the old one
+        FreeBuffer();

         InitBuffer();
     }
 }
         InitBuffer();
     }
 }


@@ -193,46 +189,67 @@ void wxStreamBuffer::ResetBuffer()
                         : m_buffer_start;
 }
 
                         : m_buffer_start;
 }
 

+void wxStreamBuffer::Truncate()
+{
+    size_t new_size = m_buffer_pos - m_buffer_start;
+    if ( m_buffer_pos == m_buffer_end )
+        return;
+
+    if ( !new_size )
+    {
+        FreeBuffer();
+        InitBuffer();
+        return;
+    }
+
+    char *new_start = (char *)realloc(m_buffer_start, new_size);
+    wxCHECK_RET( new_size, wxT("shrinking buffer shouldn't fail") );
+
+    m_buffer_start = new_start;
+    m_buffer_end = m_buffer_start + new_size;
+    m_buffer_pos = m_buffer_end;
+}
+

 // fill the buffer with as much data as possible (only for read buffers)
 bool wxStreamBuffer::FillBuffer()
 {
     wxInputStream *inStream = GetInputStream();
 
 // fill the buffer with as much data as possible (only for read buffers)
 bool wxStreamBuffer::FillBuffer()
 {
     wxInputStream *inStream = GetInputStream();
 

-    // It's legal to have no stream, so we don't complain about it just return FALSE
+    // It's legal to have no stream, so we don't complain about it just return false

     if ( !inStream )
     if ( !inStream )

-        return FALSE;
+        return false;

 
 

-    size_t count = inStream->OnSysRead(m_buffer_start, m_buffer_size);
+    size_t count = inStream->OnSysRead(GetBufferStart(), GetBufferSize());

     if ( !count )
     if ( !count )

-        return FALSE;
+        return false;

 
     m_buffer_end = m_buffer_start + count;
     m_buffer_pos = m_buffer_start;
 
 
     m_buffer_end = m_buffer_start + count;
     m_buffer_pos = m_buffer_start;
 

-    return TRUE;
+    return true;

 }
 
 // write the buffer contents to the stream (only for write buffers)
 bool wxStreamBuffer::FlushBuffer()
 {
 }
 
 // write the buffer contents to the stream (only for write buffers)
 bool wxStreamBuffer::FlushBuffer()
 {

-    wxCHECK_MSG( m_flushable, FALSE, _T("can't flush this buffer") );
+    wxCHECK_MSG( m_flushable, false, wxT("can't flush this buffer") );

 
     // FIXME: what is this check for? (VZ)
     if ( m_buffer_pos == m_buffer_start )
 
     // FIXME: what is this check for? (VZ)
     if ( m_buffer_pos == m_buffer_start )

-        return FALSE;
+        return false;

 
     wxOutputStream *outStream = GetOutputStream();
 
 
     wxOutputStream *outStream = GetOutputStream();
 

-    wxCHECK_MSG( outStream, FALSE, _T("should have a stream in wxStreamBuffer") );
+    wxCHECK_MSG( outStream, false, wxT("should have a stream in wxStreamBuffer") );

 
     size_t current = m_buffer_pos - m_buffer_start;
     size_t count = outStream->OnSysWrite(m_buffer_start, current);
     if ( count != current )
 
     size_t current = m_buffer_pos - m_buffer_start;
     size_t count = outStream->OnSysWrite(m_buffer_start, current);
     if ( count != current )

-        return FALSE;
+        return false;

 
     m_buffer_pos = m_buffer_start;
 
 
     m_buffer_pos = m_buffer_start;
 

-    return TRUE;
+    return true;

 }
 
 size_t wxStreamBuffer::GetDataLeft()
 }
 
 size_t wxStreamBuffer::GetDataLeft()


@@ -272,24 +289,26 @@ void wxStreamBuffer::PutToBuffer(const void *buffer, size_t size)
         else // !m_fixed
         {
             // realloc the buffer to have enough space for the data
         else // !m_fixed
         {
             // realloc the buffer to have enough space for the data

-            size_t delta = m_buffer_pos - m_buffer_start;
-
-            char *startOld = m_buffer_start;
-            m_buffer_size += size;
-            m_buffer_start = (char *)realloc(m_buffer_start, m_buffer_size);
-            if ( !m_buffer_start )
+            if ( m_buffer_pos + size > m_buffer_end )

             {
             {

-                // don't leak memory if realloc() failed
-                m_buffer_start = startOld;
-                m_buffer_size -= size;
+                size_t delta = m_buffer_pos - m_buffer_start;
+                size_t new_size = delta + size;

 
 

-                // what else can we do?
-                return;
-            }
+                char *startOld = m_buffer_start;
+                m_buffer_start = (char *)realloc(m_buffer_start, new_size);
+                if ( !m_buffer_start )
+                {
+                    // don't leak memory if realloc() failed
+                    m_buffer_start = startOld;
+
+                    // what else can we do?
+                    return;
+                }

 
 

-            // adjust the pointers invalidated by realloc()
-            m_buffer_pos = m_buffer_start + delta;
-            m_buffer_end = m_buffer_start + m_buffer_size;
+                // adjust the pointers invalidated by realloc()
+                m_buffer_pos = m_buffer_start + delta;
+                m_buffer_end = m_buffer_start + new_size;
+            } // else: the buffer is big enough

         }
     }
 
         }
     }
 


@@ -301,7 +320,7 @@ void wxStreamBuffer::PutChar(char c)
 {
     wxOutputStream *outStream = GetOutputStream();
 
 {
     wxOutputStream *outStream = GetOutputStream();
 

-    wxCHECK_RET( outStream, _T("should have a stream in wxStreamBuffer") );
+    wxCHECK_RET( outStream, wxT("should have a stream in wxStreamBuffer") );

 
     // if we don't have buffer at all, just forward this call to the stream,
     if ( !HasBuffer() )
 
     // if we don't have buffer at all, just forward this call to the stream,
     if ( !HasBuffer() )


@@ -327,7 +346,7 @@ void wxStreamBuffer::PutChar(char c)
 char wxStreamBuffer::Peek()
 {
     wxCHECK_MSG( m_stream && HasBuffer(), 0,
 char wxStreamBuffer::Peek()
 {
     wxCHECK_MSG( m_stream && HasBuffer(), 0,

-                 _T("should have the stream and the buffer in wxStreamBuffer") );
+                 wxT("should have the stream and the buffer in wxStreamBuffer") );

 
     if ( !GetDataLeft() )
     {
 
     if ( !GetDataLeft() )
     {


@@ -346,7 +365,7 @@ char wxStreamBuffer::GetChar()
 {
     wxInputStream *inStream = GetInputStream();
 
 {
     wxInputStream *inStream = GetInputStream();
 

-    wxCHECK_MSG( inStream, 0, _T("should have a stream in wxStreamBuffer") );
+    wxCHECK_MSG( inStream, 0, wxT("should have a stream in wxStreamBuffer") );

 
     char c;
     if ( !HasBuffer() )
 
     char c;
     if ( !HasBuffer() )


@@ -372,18 +391,23 @@ char wxStreamBuffer::GetChar()
 
 size_t wxStreamBuffer::Read(void *buffer, size_t size)
 {
 
 size_t wxStreamBuffer::Read(void *buffer, size_t size)
 {

+    wxASSERT_MSG( buffer, wxT("Warning: Null pointer is about to be used") );
+
+    /* Clear buffer first */
+    memset(buffer, 0x00, size);
+

     // lasterror is reset before all new IO calls
     if ( m_stream )
         m_stream->Reset();
 
     // lasterror is reset before all new IO calls
     if ( m_stream )
         m_stream->Reset();
 

-    size_t read;
+    size_t readBytes;

     if ( !HasBuffer() )
     {
         wxInputStream *inStream = GetInputStream();
 
     if ( !HasBuffer() )
     {
         wxInputStream *inStream = GetInputStream();
 

-        wxCHECK_MSG( inStream, 0, _T("should have a stream in wxStreamBuffer") );
+        wxCHECK_MSG( inStream, 0, wxT("should have a stream in wxStreamBuffer") );

 
 

-        read = inStream->OnSysRead(buffer, size);
+        readBytes = inStream->OnSysRead(buffer, size);

     }
     else // we have a buffer, use it
     {
     }
     else // we have a buffer, use it
     {


@@ -414,19 +438,19 @@ size_t wxStreamBuffer::Read(void *buffer, size_t size)
             }
         }
 
             }
         }
 

-        read = orig_size - size;
+        readBytes = orig_size - size;

     }
 
     if ( m_stream )
     }
 
     if ( m_stream )

-        m_stream->m_lastcount = read;
+        m_stream->m_lastcount = readBytes;

 
 

-    return read;
+    return readBytes;

 }
 
 // this should really be called "Copy()"
 size_t wxStreamBuffer::Read(wxStreamBuffer *dbuf)
 {
 }
 
 // this should really be called "Copy()"
 size_t wxStreamBuffer::Read(wxStreamBuffer *dbuf)
 {

-    wxCHECK_MSG( m_mode != write, 0, _T("can't read from this buffer") );
+    wxCHECK_MSG( m_mode != write, 0, wxT("can't read from this buffer") );

 
     char buf[BUF_TEMP_SIZE];
     size_t nRead,
 
     char buf[BUF_TEMP_SIZE];
     size_t nRead,


@@ -434,7 +458,7 @@ size_t wxStreamBuffer::Read(wxStreamBuffer *dbuf)
 
     do
     {
 
     do
     {

-        nRead = Read(dbuf, WXSIZEOF(buf));
+        nRead = Read(buf, WXSIZEOF(buf));

         if ( nRead )
         {
             nRead = dbuf->Write(buf, nRead);
         if ( nRead )
         {
             nRead = dbuf->Write(buf, nRead);


@@ -448,6 +472,8 @@ size_t wxStreamBuffer::Read(wxStreamBuffer *dbuf)
 
 size_t wxStreamBuffer::Write(const void *buffer, size_t size)
 {
 
 size_t wxStreamBuffer::Write(const void *buffer, size_t size)
 {

+    wxASSERT_MSG( buffer, wxT("Warning: Null pointer is about to be send") );
+

     if (m_stream)
     {
         // lasterror is reset before all new IO calls
     if (m_stream)
     {
         // lasterror is reset before all new IO calls


@@ -460,7 +486,7 @@ size_t wxStreamBuffer::Write(const void *buffer, size_t size)
     {
         wxOutputStream *outStream = GetOutputStream();
 
     {
         wxOutputStream *outStream = GetOutputStream();
 

-        wxCHECK_MSG( outStream, 0, _T("should have a stream in wxStreamBuffer") );
+        wxCHECK_MSG( outStream, 0, wxT("should have a stream in wxStreamBuffer") );

 
         // no buffer, just forward the call to the stream
         ret = outStream->OnSysWrite(buffer, size);
 
         // no buffer, just forward the call to the stream
         ret = outStream->OnSysWrite(buffer, size);


@@ -518,8 +544,8 @@ size_t wxStreamBuffer::Write(const void *buffer, size_t size)
 
 size_t wxStreamBuffer::Write(wxStreamBuffer *sbuf)
 {
 
 size_t wxStreamBuffer::Write(wxStreamBuffer *sbuf)
 {

-    wxCHECK_MSG( m_mode != read, 0, _T("can't write to this buffer") );
-    wxCHECK_MSG( sbuf->m_mode != write, 0, _T("can't read from that buffer") );
+    wxCHECK_MSG( m_mode != read, 0, wxT("can't write to this buffer") );
+    wxCHECK_MSG( sbuf->m_mode != write, 0, wxT("can't read from that buffer") );

 
     char buf[BUF_TEMP_SIZE];
     size_t nWrite,
 
     char buf[BUF_TEMP_SIZE];
     size_t nWrite,


@@ -551,11 +577,11 @@ size_t wxStreamBuffer::Write(wxStreamBuffer *sbuf)
     return total;
 }
 
     return total;
 }
 

-off_t wxStreamBuffer::Seek(off_t pos, wxSeekMode mode)
+wxFileOffset wxStreamBuffer::Seek(wxFileOffset pos, wxSeekMode mode)

 {
 {

-    off_t ret_off, diff;
+    wxFileOffset ret_off, diff;

 
 

-    off_t last_access = GetLastAccess();
+    wxFileOffset last_access = GetLastAccess();

 
     if ( !m_flushable )
     {
 
     if ( !m_flushable )
     {


@@ -574,13 +600,15 @@ off_t wxStreamBuffer::Seek(off_t pos, wxSeekMode mode)
                 break;
 
             default:
                 break;
 
             default:

-                wxFAIL_MSG( _T("invalid seek mode") );
+                wxFAIL_MSG( wxT("invalid seek mode") );

 
                 return wxInvalidOffset;
         }
         if (diff < 0 || diff > last_access)
             return wxInvalidOffset;
 
                 return wxInvalidOffset;
         }
         if (diff < 0 || diff > last_access)
             return wxInvalidOffset;

-        SetIntPosition(diff);
+        size_t int_diff = wx_truncate_cast(size_t, diff);
+        wxCHECK_MSG( (wxFileOffset)int_diff == diff, wxInvalidOffset, wxT("huge file not supported") );
+        SetIntPosition(int_diff);

         return diff;
     }
 
         return diff;
     }
 


@@ -605,8 +633,10 @@ off_t wxStreamBuffer::Seek(off_t pos, wxSeekMode mode)
             }
             else
             {
             }
             else
             {

-                SetIntPosition(diff);
-                return pos;
+                size_t int_diff = wx_truncate_cast(size_t, diff);
+                wxCHECK_MSG( (wxFileOffset)int_diff == diff, wxInvalidOffset, wxT("huge file not supported") );
+                SetIntPosition(int_diff);
+                return diff;

             }
 
         case wxFromEnd:
             }
 
         case wxFromEnd:


@@ -619,9 +649,9 @@ off_t wxStreamBuffer::Seek(off_t pos, wxSeekMode mode)
     return wxInvalidOffset;
 }
 
     return wxInvalidOffset;
 }
 

-off_t wxStreamBuffer::Tell() const
+wxFileOffset wxStreamBuffer::Tell() const

 {
 {

-    off_t pos;
+    wxFileOffset pos;

 
     // ask the stream for position if we have a real one
     if ( m_stream )
 
     // ask the stream for position if we have a real one
     if ( m_stream )


@@ -647,6 +677,8 @@ off_t wxStreamBuffer::Tell() const
 // wxStreamBase
 // ----------------------------------------------------------------------------
 
 // wxStreamBase
 // ----------------------------------------------------------------------------
 

+IMPLEMENT_ABSTRACT_CLASS(wxStreamBase, wxObject)
+

 wxStreamBase::wxStreamBase()
 {
     m_lasterror = wxSTREAM_NO_ERROR;
 wxStreamBase::wxStreamBase()
 {
     m_lasterror = wxSTREAM_NO_ERROR;


@@ -657,12 +689,24 @@ wxStreamBase::~wxStreamBase()
 {
 }
 
 {
 }
 

-off_t wxStreamBase::OnSysSeek(off_t WXUNUSED(seek), wxSeekMode WXUNUSED(mode))
+size_t wxStreamBase::GetSize() const
+{
+    wxFileOffset length = GetLength();
+    if ( length == (wxFileOffset)wxInvalidOffset )
+        return 0;
+
+    const size_t len = wx_truncate_cast(size_t, length);
+    wxASSERT_MSG( len == length + size_t(0), wxT("large files not supported") );
+
+    return len;
+}
+
+wxFileOffset wxStreamBase::OnSysSeek(wxFileOffset WXUNUSED(seek), wxSeekMode WXUNUSED(mode))

 {
     return wxInvalidOffset;
 }
 
 {
     return wxInvalidOffset;
 }
 

-off_t wxStreamBase::OnSysTell() const
+wxFileOffset wxStreamBase::OnSysTell() const

 {
     return wxInvalidOffset;
 }
 {
     return wxInvalidOffset;
 }


@@ -671,6 +715,8 @@ off_t wxStreamBase::OnSysTell() const
 // wxInputStream
 // ----------------------------------------------------------------------------
 
 // wxInputStream
 // ----------------------------------------------------------------------------
 

+IMPLEMENT_ABSTRACT_CLASS(wxInputStream, wxStreamBase)
+

 wxInputStream::wxInputStream()
 {
     m_wback = NULL;
 wxInputStream::wxInputStream()
 {
     m_wback = NULL;


@@ -726,6 +772,11 @@ char *wxInputStream::AllocSpaceWBack(size_t needed_size)
 
 size_t wxInputStream::GetWBack(void *buf, size_t size)
 {
 
 size_t wxInputStream::GetWBack(void *buf, size_t size)
 {

+    wxASSERT_MSG( buf, wxT("Warning: Null pointer is about to be used") );
+
+    /* Clear buffer first */
+    memset(buf, 0x00, size);
+

     if (!m_wback)
         return 0;
 
     if (!m_wback)
         return 0;
 


@@ -757,6 +808,8 @@ size_t wxInputStream::GetWBack(void *buf, size_t size)
 
 size_t wxInputStream::Ungetch(const void *buf, size_t bufsize)
 {
 
 size_t wxInputStream::Ungetch(const void *buf, size_t bufsize)
 {

+    wxASSERT_MSG( buf, wxT("Warning: Null pointer is about to be used in Ungetch()") );
+

     if ( m_lasterror != wxSTREAM_NO_ERROR && m_lasterror != wxSTREAM_EOF )
     {
         // can't operate on this stream until the error is cleared
     if ( m_lasterror != wxSTREAM_NO_ERROR && m_lasterror != wxSTREAM_EOF )
     {
         // can't operate on this stream until the error is cleared


@@ -767,7 +820,7 @@ size_t wxInputStream::Ungetch(const void *buf, size_t bufsize)
     if (!ptrback)
         return 0;
 
     if (!ptrback)
         return 0;
 

-    // Eof() shouldn't return TRUE any longer
+    // Eof() shouldn't return true any longer

     if ( m_lasterror == wxSTREAM_EOF )
         m_lasterror = wxSTREAM_NO_ERROR;
 
     if ( m_lasterror == wxSTREAM_EOF )
         m_lasterror = wxSTREAM_NO_ERROR;
 


@@ -780,15 +833,17 @@ bool wxInputStream::Ungetch(char c)
     return Ungetch(&c, sizeof(c)) != 0;
 }
 
     return Ungetch(&c, sizeof(c)) != 0;
 }
 

-char wxInputStream::GetC()
+int wxInputStream::GetC()

 {
 {

-    char c;
+    unsigned char c;

     Read(&c, sizeof(c));
     Read(&c, sizeof(c));

-    return c;
+    return LastRead() ? c : wxEOF;

 }
 
 wxInputStream& wxInputStream::Read(void *buf, size_t size)
 {
 }
 
 wxInputStream& wxInputStream::Read(void *buf, size_t size)
 {

+    wxASSERT_MSG( buf, wxT("Warning: Null pointer is about to be read") );
+

     char *p = (char *)buf;
     m_lastcount = 0;
 
     char *p = (char *)buf;
     m_lastcount = 0;
 


@@ -838,6 +893,7 @@ char wxInputStream::Peek()
 
 wxInputStream& wxInputStream::Read(wxOutputStream& stream_out)
 {
 
 wxInputStream& wxInputStream::Read(wxOutputStream& stream_out)
 {

+    size_t lastcount = 0;

     char buf[BUF_TEMP_SIZE];
 
     for ( ;; )
     char buf[BUF_TEMP_SIZE];
 
     for ( ;; )


@@ -848,22 +904,61 @@ wxInputStream& wxInputStream::Read(wxOutputStream& stream_out)
 
         if ( stream_out.Write(buf, bytes_read).LastWrite() != bytes_read )
             break;
 
         if ( stream_out.Write(buf, bytes_read).LastWrite() != bytes_read )
             break;

+
+        lastcount += bytes_read;

     }
 
     }
 

+    m_lastcount = lastcount;
+

     return *this;
 }
 
     return *this;
 }
 

-off_t wxInputStream::SeekI(off_t pos, wxSeekMode mode)
+wxFileOffset wxInputStream::SeekI(wxFileOffset pos, wxSeekMode mode)

 {
     // RR: This code is duplicated in wxBufferedInputStream. This is
     // not really a good design, but buffered stream are different
 {
     // RR: This code is duplicated in wxBufferedInputStream. This is
     // not really a good design, but buffered stream are different

-    // from all other in that they handle two stream-related objects,
+    // from all others in that they handle two stream-related objects:

     // the stream buffer and parent stream.
 
     // I don't know whether it should be put as well in wxFileInputStream::OnSysSeek
     if (m_lasterror==wxSTREAM_EOF)
         m_lasterror=wxSTREAM_NO_ERROR;
 
     // the stream buffer and parent stream.
 
     // I don't know whether it should be put as well in wxFileInputStream::OnSysSeek
     if (m_lasterror==wxSTREAM_EOF)
         m_lasterror=wxSTREAM_NO_ERROR;
 

+    // avoid unnecessary seek operations (optimization)
+    wxFileOffset currentPos = TellI(), size = GetLength();
+    if ((mode == wxFromStart && currentPos == pos) ||
+        (mode == wxFromCurrent && pos == 0) ||
+        (mode == wxFromEnd && size != wxInvalidOffset && currentPos == size-pos))
+        return currentPos;
+
+    if (!IsSeekable() && mode == wxFromCurrent && pos > 0)
+    {
+        // rather than seeking, we can just read data and discard it;
+        // this allows to forward-seek also non-seekable streams!
+        char buf[BUF_TEMP_SIZE];
+        size_t bytes_read;
+
+        // read chunks of BUF_TEMP_SIZE bytes until we reach the new position
+        for ( ; pos >= BUF_TEMP_SIZE; pos -= bytes_read)
+        {
+            bytes_read = Read(buf, WXSIZEOF(buf)).LastRead();
+            if ( m_lasterror != wxSTREAM_NO_ERROR )
+                return wxInvalidOffset;
+
+            wxASSERT(bytes_read == WXSIZEOF(buf));
+        }
+
+        // read the last 'pos' bytes
+        bytes_read = Read(buf, (size_t)pos).LastRead();
+        if ( m_lasterror != wxSTREAM_NO_ERROR )
+            return wxInvalidOffset;
+
+        wxASSERT(bytes_read == (size_t)pos);
+
+        // we should now have sought to the right position...
+        return TellI();
+    }
+

     /* RR: A call to SeekI() will automatically invalidate any previous
        call to Ungetch(), otherwise it would be possible to SeekI() to
        one position, unread some bytes there, SeekI() to another position
     /* RR: A call to SeekI() will automatically invalidate any previous
        call to Ungetch(), otherwise it would be possible to SeekI() to
        one position, unread some bytes there, SeekI() to another position


@@ -887,9 +982,9 @@ off_t wxInputStream::SeekI(off_t pos, wxSeekMode mode)
     return OnSysSeek(pos, mode);
 }
 
     return OnSysSeek(pos, mode);
 }
 

-off_t wxInputStream::TellI() const
+wxFileOffset wxInputStream::TellI() const

 {
 {

-    off_t pos = OnSysTell();
+    wxFileOffset pos = OnSysTell();

 
     if (pos != wxInvalidOffset)
         pos -= (m_wbacksize - m_wbackcur);
 
     if (pos != wxInvalidOffset)
         pos -= (m_wbacksize - m_wbackcur);


@@ -902,6 +997,8 @@ off_t wxInputStream::TellI() const
 // wxOutputStream
 // ----------------------------------------------------------------------------
 
 // wxOutputStream
 // ----------------------------------------------------------------------------
 

+IMPLEMENT_ABSTRACT_CLASS(wxOutputStream, wxStreamBase)
+

 wxOutputStream::wxOutputStream()
 {
 }
 wxOutputStream::wxOutputStream()
 {
 }


@@ -933,12 +1030,12 @@ wxOutputStream& wxOutputStream::Write(wxInputStream& stream_in)
     return *this;
 }
 
     return *this;
 }
 

-off_t wxOutputStream::TellO() const
+wxFileOffset wxOutputStream::TellO() const

 {
     return OnSysTell();
 }
 
 {
     return OnSysTell();
 }
 

-off_t wxOutputStream::SeekO(off_t pos, wxSeekMode mode)
+wxFileOffset wxOutputStream::SeekO(wxFileOffset pos, wxSeekMode mode)

 {
     return OnSysSeek(pos, mode);
 }
 {
     return OnSysSeek(pos, mode);
 }


@@ -952,12 +1049,14 @@ void wxOutputStream::Sync()
 // wxCountingOutputStream
 // ----------------------------------------------------------------------------
 
 // wxCountingOutputStream
 // ----------------------------------------------------------------------------
 

+IMPLEMENT_DYNAMIC_CLASS(wxCountingOutputStream, wxOutputStream)
+

 wxCountingOutputStream::wxCountingOutputStream ()
 {
      m_currentPos = 0;
 }
 
 wxCountingOutputStream::wxCountingOutputStream ()
 {
      m_currentPos = 0;
 }
 

-size_t wxCountingOutputStream::GetSize() const
+wxFileOffset wxCountingOutputStream::GetLength() const

 {
     return m_lastcount;
 }
 {
     return m_lastcount;
 }


@@ -972,34 +1071,40 @@ size_t wxCountingOutputStream::OnSysWrite(const void *WXUNUSED(buffer),
     return m_currentPos;
 }
 
     return m_currentPos;
 }
 

-off_t wxCountingOutputStream::OnSysSeek(off_t pos, wxSeekMode mode)
+wxFileOffset wxCountingOutputStream::OnSysSeek(wxFileOffset pos, wxSeekMode mode)

 {
 {

+    ssize_t new_pos = wx_truncate_cast(ssize_t, pos);
+

     switch ( mode )
     {
         case wxFromStart:
     switch ( mode )
     {
         case wxFromStart:

-            m_currentPos = pos;
+            wxCHECK_MSG( (wxFileOffset)new_pos == pos, wxInvalidOffset, wxT("huge position not supported") );

             break;
 
         case wxFromEnd:
             break;
 
         case wxFromEnd:

-            m_currentPos = m_lastcount + pos;
+            new_pos = m_lastcount + new_pos;
+            wxCHECK_MSG( (wxFileOffset)new_pos == (wxFileOffset)(m_lastcount + pos), wxInvalidOffset, wxT("huge position not supported") );

             break;
 
         case wxFromCurrent:
             break;
 
         case wxFromCurrent:

-            m_currentPos += pos;
+            new_pos = m_currentPos + new_pos;
+            wxCHECK_MSG( (wxFileOffset)new_pos == (wxFileOffset)(m_currentPos + pos), wxInvalidOffset, wxT("huge position not supported") );

             break;
 
         default:
             break;
 
         default:

-            wxFAIL_MSG( _T("invalid seek mode") );
+            wxFAIL_MSG( wxT("invalid seek mode") );

             return wxInvalidOffset;
     }
 
             return wxInvalidOffset;
     }
 

+    m_currentPos = new_pos;
+

     if (m_currentPos > m_lastcount)
         m_lastcount = m_currentPos;
 
     return m_currentPos;
 }
 
     if (m_currentPos > m_lastcount)
         m_lastcount = m_currentPos;
 
     return m_currentPos;
 }
 

-off_t wxCountingOutputStream::OnSysTell() const
+wxFileOffset wxCountingOutputStream::OnSysTell() const

 {
     return m_currentPos;
 }
 {
     return m_currentPos;
 }


@@ -1008,62 +1113,165 @@ off_t wxCountingOutputStream::OnSysTell() const
 // wxFilterInputStream
 // ----------------------------------------------------------------------------
 
 // wxFilterInputStream
 // ----------------------------------------------------------------------------
 

+IMPLEMENT_ABSTRACT_CLASS(wxFilterInputStream, wxInputStream)
+

 wxFilterInputStream::wxFilterInputStream()
 wxFilterInputStream::wxFilterInputStream()

+ :  m_parent_i_stream(NULL),
+    m_owns(false)

 {
 {

-    m_parent_i_stream = NULL;

 }
 
 wxFilterInputStream::wxFilterInputStream(wxInputStream& stream)
 }
 
 wxFilterInputStream::wxFilterInputStream(wxInputStream& stream)

+ :  m_parent_i_stream(&stream),
+    m_owns(false)
+{
+}
+
+wxFilterInputStream::wxFilterInputStream(wxInputStream *stream)
+ :  m_parent_i_stream(stream),
+    m_owns(true)

 {
 {

-    m_parent_i_stream = &stream;

 }
 
 wxFilterInputStream::~wxFilterInputStream()
 {
 }
 
 wxFilterInputStream::~wxFilterInputStream()
 {

+    if (m_owns)
+        delete m_parent_i_stream;

 }
 
 // ----------------------------------------------------------------------------
 // wxFilterOutputStream
 // ----------------------------------------------------------------------------
 
 }
 
 // ----------------------------------------------------------------------------
 // wxFilterOutputStream
 // ----------------------------------------------------------------------------
 

+IMPLEMENT_ABSTRACT_CLASS(wxFilterOutputStream, wxOutputStream)
+

 wxFilterOutputStream::wxFilterOutputStream()
 wxFilterOutputStream::wxFilterOutputStream()

+ :  m_parent_o_stream(NULL),
+    m_owns(false)

 {
 {

-    m_parent_o_stream = NULL;

 }
 
 wxFilterOutputStream::wxFilterOutputStream(wxOutputStream& stream)
 }
 
 wxFilterOutputStream::wxFilterOutputStream(wxOutputStream& stream)

+ :  m_parent_o_stream(&stream),
+    m_owns(false)
+{
+}
+
+wxFilterOutputStream::wxFilterOutputStream(wxOutputStream *stream)
+ :  m_parent_o_stream(stream),
+    m_owns(true)

 {
 {

-    m_parent_o_stream = &stream;
+}
+
+bool wxFilterOutputStream::Close()
+{
+    if (m_parent_o_stream && m_owns)
+        return m_parent_o_stream->Close();
+    else
+        return true;

 }
 
 wxFilterOutputStream::~wxFilterOutputStream()
 {
 }
 
 wxFilterOutputStream::~wxFilterOutputStream()
 {

+    if (m_owns)
+        delete m_parent_o_stream;

 }
 
 // ----------------------------------------------------------------------------
 }
 
 // ----------------------------------------------------------------------------

-// wxBufferedInputStream
+// wxFilterClassFactoryBase

 // ----------------------------------------------------------------------------
 
 // ----------------------------------------------------------------------------
 

-wxBufferedInputStream::wxBufferedInputStream(wxInputStream& s,
-                                             wxStreamBuffer *buffer)
-                     : wxFilterInputStream(s)
+IMPLEMENT_ABSTRACT_CLASS(wxFilterClassFactoryBase, wxObject)
+
+wxString wxFilterClassFactoryBase::PopExtension(const wxString& location) const

 {
 {

-    if ( buffer )
+    return location.substr(0, FindExtension(location));
+}
+
+wxString::size_type wxFilterClassFactoryBase::FindExtension(
+        const wxString& location) const
+{
+    for (const wxChar *const *p = GetProtocols(wxSTREAM_FILEEXT); *p; p++)

     {
     {

-        // use the buffer provided by the user
-        m_i_streambuf = buffer;
+        if ( location.EndsWith(*p) )
+            return location.length() - wxStrlen(*p);

     }
     }

-    else // create a default buffer
+
+    return wxString::npos;
+}
+
+bool wxFilterClassFactoryBase::CanHandle(const wxString& protocol,
+                                         wxStreamProtocolType type) const
+{
+    if (type == wxSTREAM_FILEEXT)
+        return FindExtension(protocol) != wxString::npos;
+    else
+        for (const wxChar *const *p = GetProtocols(type); *p; p++)
+            if (protocol == *p)
+                return true;
+
+    return false;
+}
+
+// ----------------------------------------------------------------------------
+// wxFilterClassFactory
+// ----------------------------------------------------------------------------
+
+IMPLEMENT_ABSTRACT_CLASS(wxFilterClassFactory, wxFilterClassFactoryBase)
+
+wxFilterClassFactory *wxFilterClassFactory::sm_first = NULL;
+
+void wxFilterClassFactory::Remove()
+{
+    if (m_next != this)

     {
     {

-        m_i_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::read);
+        wxFilterClassFactory **pp = &sm_first;
+
+        while (*pp != this)
+            pp = &(*pp)->m_next;
+
+        *pp = m_next;

 
 

-        m_i_streambuf->SetBufferIO(1024);
+        m_next = this;

     }
 }
 
     }
 }
 

+// ----------------------------------------------------------------------------
+// wxBufferedInputStream
+// ----------------------------------------------------------------------------
+
+namespace
+{
+
+// helper function used for initializing the buffer used by
+// wxBufferedInput/OutputStream: it simply returns the provided buffer if it's
+// not NULL or creates a buffer of the given size otherwise
+template <typename T>
+wxStreamBuffer *
+CreateBufferIfNeeded(T& stream, wxStreamBuffer *buffer, size_t bufsize = 1024)
+{
+    return buffer ? buffer : new wxStreamBuffer(bufsize, stream);
+}
+
+} // anonymous namespace
+
+wxBufferedInputStream::wxBufferedInputStream(wxInputStream& stream,
+                                             wxStreamBuffer *buffer)
+                     : wxFilterInputStream(stream)
+{
+    m_i_streambuf = CreateBufferIfNeeded(*this, buffer);
+}
+
+wxBufferedInputStream::wxBufferedInputStream(wxInputStream& stream,
+                                             size_t bufsize)
+                     : wxFilterInputStream(stream)
+{
+    m_i_streambuf = CreateBufferIfNeeded(*this, NULL, bufsize);
+}
+

 wxBufferedInputStream::~wxBufferedInputStream()
 {
 wxBufferedInputStream::~wxBufferedInputStream()
 {

-    m_parent_i_stream->SeekI(-(off_t)m_i_streambuf->GetBytesLeft(),
+    m_parent_i_stream->SeekI(-(wxFileOffset)m_i_streambuf->GetBytesLeft(),

                              wxFromCurrent);
 
     delete m_i_streambuf;
                              wxFromCurrent);
 
     delete m_i_streambuf;


@@ -1088,19 +1296,22 @@ wxInputStream& wxBufferedInputStream::Read(void *buf, size_t size)
         size -= m_lastcount;
         buf = (char *)buf + m_lastcount;
 
         size -= m_lastcount;
         buf = (char *)buf + m_lastcount;
 

-        // the call to wxStreamBuffer::Read() below will reset our m_lastcount,
-        // so save it
+        // the call to wxStreamBuffer::Read() below may reset our m_lastcount
+        // (but it also may not do it if the buffer is associated to another
+        // existing stream and wasn't created by us), so save it

         size_t countOld = m_lastcount;
 
         size_t countOld = m_lastcount;
 

-        m_i_streambuf->Read(buf, size);
+        // the new count of the bytes read is the count of bytes read this time
+        m_lastcount = m_i_streambuf->Read(buf, size);

 
 

+        // plus those we had read before

         m_lastcount += countOld;
     }
 
     return *this;
 }
 
         m_lastcount += countOld;
     }
 
     return *this;
 }
 

-off_t wxBufferedInputStream::SeekI(off_t pos, wxSeekMode mode)
+wxFileOffset wxBufferedInputStream::SeekI(wxFileOffset pos, wxSeekMode mode)

 {
     // RR: Look at wxInputStream for comments.
 
 {
     // RR: Look at wxInputStream for comments.
 


@@ -1120,9 +1331,9 @@ off_t wxBufferedInputStream::SeekI(off_t pos, wxSeekMode mode)
     return m_i_streambuf->Seek(pos, mode);
 }
 
     return m_i_streambuf->Seek(pos, mode);
 }
 

-off_t wxBufferedInputStream::TellI() const
+wxFileOffset wxBufferedInputStream::TellI() const

 {
 {

-    off_t pos = m_i_streambuf->Tell();
+    wxFileOffset pos = m_i_streambuf->Tell();

 
     if (pos != wxInvalidOffset)
         pos -= (m_wbacksize - m_wbackcur);
 
     if (pos != wxInvalidOffset)
         pos -= (m_wbacksize - m_wbackcur);


@@ -1135,19 +1346,19 @@ size_t wxBufferedInputStream::OnSysRead(void *buffer, size_t bufsize)
     return m_parent_i_stream->Read(buffer, bufsize).LastRead();
 }
 
     return m_parent_i_stream->Read(buffer, bufsize).LastRead();
 }
 

-off_t wxBufferedInputStream::OnSysSeek(off_t seek, wxSeekMode mode)
+wxFileOffset wxBufferedInputStream::OnSysSeek(wxFileOffset seek, wxSeekMode mode)

 {
     return m_parent_i_stream->SeekI(seek, mode);
 }
 
 {
     return m_parent_i_stream->SeekI(seek, mode);
 }
 

-off_t wxBufferedInputStream::OnSysTell() const
+wxFileOffset wxBufferedInputStream::OnSysTell() const

 {
     return m_parent_i_stream->TellI();
 }
 
 void wxBufferedInputStream::SetInputStreamBuffer(wxStreamBuffer *buffer)
 {
 {
     return m_parent_i_stream->TellI();
 }
 
 void wxBufferedInputStream::SetInputStreamBuffer(wxStreamBuffer *buffer)
 {

-    wxCHECK_RET( buffer, _T("wxBufferedInputStream needs buffer") );
+    wxCHECK_RET( buffer, wxT("wxBufferedInputStream needs buffer") );

 
     delete m_i_streambuf;
     m_i_streambuf = buffer;
 
     delete m_i_streambuf;
     m_i_streambuf = buffer;


@@ -1157,20 +1368,18 @@ void wxBufferedInputStream::SetInputStreamBuffer(wxStreamBuffer *buffer)
 // wxBufferedOutputStream
 // ----------------------------------------------------------------------------
 
 // wxBufferedOutputStream
 // ----------------------------------------------------------------------------
 

-wxBufferedOutputStream::wxBufferedOutputStream(wxOutputStream& s,
+wxBufferedOutputStream::wxBufferedOutputStream(wxOutputStream& stream,

                                                wxStreamBuffer *buffer)
                                                wxStreamBuffer *buffer)

-                      : wxFilterOutputStream(s)
+                      : wxFilterOutputStream(stream)

 {
 {

-    if ( buffer )
-    {
-        m_o_streambuf = buffer;
-    }
-    else // create a default one
-    {
-        m_o_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::write);
+    m_o_streambuf = CreateBufferIfNeeded(*this, buffer);
+}

 
 

-        m_o_streambuf->SetBufferIO(1024);
-    }
+wxBufferedOutputStream::wxBufferedOutputStream(wxOutputStream& stream,
+                                               size_t bufsize)
+                      : wxFilterOutputStream(stream)
+{
+    m_o_streambuf = CreateBufferIfNeeded(*this, NULL, bufsize);

 }
 
 wxBufferedOutputStream::~wxBufferedOutputStream()
 }
 
 wxBufferedOutputStream::~wxBufferedOutputStream()


@@ -1179,6 +1388,13 @@ wxBufferedOutputStream::~wxBufferedOutputStream()
     delete m_o_streambuf;
 }
 
     delete m_o_streambuf;
 }
 

+bool wxBufferedOutputStream::Close()
+{
+    Sync();
+    return IsOk();
+}
+
+

 wxOutputStream& wxBufferedOutputStream::Write(const void *buffer, size_t size)
 {
     m_lastcount = 0;
 wxOutputStream& wxBufferedOutputStream::Write(const void *buffer, size_t size)
 {
     m_lastcount = 0;


@@ -1186,13 +1402,13 @@ wxOutputStream& wxBufferedOutputStream::Write(const void *buffer, size_t size)
     return *this;
 }
 
     return *this;
 }
 

-off_t wxBufferedOutputStream::SeekO(off_t pos, wxSeekMode mode)
+wxFileOffset wxBufferedOutputStream::SeekO(wxFileOffset pos, wxSeekMode mode)

 {
     Sync();
     return m_o_streambuf->Seek(pos, mode);
 }
 
 {
     Sync();
     return m_o_streambuf->Seek(pos, mode);
 }
 

-off_t wxBufferedOutputStream::TellO() const
+wxFileOffset wxBufferedOutputStream::TellO() const

 {
     return m_o_streambuf->Tell();
 }
 {
     return m_o_streambuf->Tell();
 }


@@ -1208,29 +1424,116 @@ size_t wxBufferedOutputStream::OnSysWrite(const void *buffer, size_t bufsize)
     return m_parent_o_stream->Write(buffer, bufsize).LastWrite();
 }
 
     return m_parent_o_stream->Write(buffer, bufsize).LastWrite();
 }
 

-off_t wxBufferedOutputStream::OnSysSeek(off_t seek, wxSeekMode mode)
+wxFileOffset wxBufferedOutputStream::OnSysSeek(wxFileOffset seek, wxSeekMode mode)

 {
     return m_parent_o_stream->SeekO(seek, mode);
 }
 
 {
     return m_parent_o_stream->SeekO(seek, mode);
 }
 

-off_t wxBufferedOutputStream::OnSysTell() const
+wxFileOffset wxBufferedOutputStream::OnSysTell() const

 {
     return m_parent_o_stream->TellO();
 }
 
 {
     return m_parent_o_stream->TellO();
 }
 

-size_t wxBufferedOutputStream::GetSize() const
+wxFileOffset wxBufferedOutputStream::GetLength() const

 {
 {

-   return m_parent_o_stream->GetSize() + m_o_streambuf->GetIntPosition();
+   return m_parent_o_stream->GetLength() + m_o_streambuf->GetIntPosition();

 }
 
 void wxBufferedOutputStream::SetOutputStreamBuffer(wxStreamBuffer *buffer)
 {
 }
 
 void wxBufferedOutputStream::SetOutputStreamBuffer(wxStreamBuffer *buffer)
 {

-    wxCHECK_RET( buffer, _T("wxBufferedOutputStream needs buffer") );
+    wxCHECK_RET( buffer, wxT("wxBufferedOutputStream needs buffer") );

 
     delete m_o_streambuf;
     m_o_streambuf = buffer;
 }
 
 
     delete m_o_streambuf;
     m_o_streambuf = buffer;
 }
 

+// ---------------------------------------------------------------------------
+// wxWrapperInputStream implementation
+// ---------------------------------------------------------------------------
+
+wxWrapperInputStream::wxWrapperInputStream()
+{
+    m_lasterror = wxSTREAM_READ_ERROR;
+}
+
+wxWrapperInputStream::wxWrapperInputStream(wxInputStream& stream)
+    : wxFilterInputStream(stream)
+{
+    SynchronizeLastError();
+}
+
+wxWrapperInputStream::wxWrapperInputStream(wxInputStream *stream)
+    : wxFilterInputStream(stream)
+{
+    if ( m_parent_i_stream )
+        SynchronizeLastError();
+    else
+        m_lasterror = wxSTREAM_READ_ERROR;
+}
+
+void wxWrapperInputStream::InitParentStream(wxInputStream& stream)
+{
+    wxCHECK_RET( !m_parent_i_stream, "Can't init parent stream twice" );
+
+    m_parent_i_stream = &stream;
+
+    SynchronizeLastError();
+}
+
+void wxWrapperInputStream::InitParentStream(wxInputStream* stream)
+{
+    wxCHECK_RET( !m_parent_i_stream, "Can't init parent stream twice" );
+
+    m_parent_i_stream = stream;
+
+    if ( m_parent_i_stream )
+    {
+        m_owns = true;
+
+        SynchronizeLastError();
+    }
+}
+
+wxFileOffset wxWrapperInputStream::GetLength() const
+{
+    wxCHECK_MSG(m_parent_i_stream, wxInvalidOffset, "Stream not valid");
+
+    wxON_BLOCK_EXIT_THIS0(wxWrapperInputStream::SynchronizeLastError);
+    return m_parent_i_stream->GetLength();
+}
+
+bool wxWrapperInputStream::IsSeekable() const
+{
+    wxCHECK_MSG(m_parent_i_stream, false, "Stream not valid");
+    return m_parent_i_stream->IsSeekable();
+}
+
+size_t wxWrapperInputStream::OnSysRead(void *buffer, size_t size)
+{
+    wxCHECK_MSG(m_parent_i_stream, false, "Stream not valid");
+
+    wxON_BLOCK_EXIT_THIS0(wxWrapperInputStream::SynchronizeLastError);
+
+    m_parent_i_stream->Read(buffer, size);
+    return m_parent_i_stream->LastRead();
+}
+
+wxFileOffset wxWrapperInputStream::OnSysSeek(wxFileOffset pos, wxSeekMode mode)
+{
+    wxCHECK_MSG(IsSeekable(), false, "Stream not seekable");
+
+    wxON_BLOCK_EXIT_THIS0(wxWrapperInputStream::SynchronizeLastError);
+    return m_parent_i_stream->SeekI (pos, mode);
+}
+
+wxFileOffset wxWrapperInputStream::OnSysTell() const
+{
+    wxCHECK_MSG(m_parent_i_stream, false, "Stream not valid");
+
+    wxON_BLOCK_EXIT_THIS0(wxWrapperInputStream::SynchronizeLastError);
+    return m_parent_i_stream->TellI();
+}
+

 // ----------------------------------------------------------------------------
 // Some IOManip function
 // ----------------------------------------------------------------------------
 // ----------------------------------------------------------------------------
 // Some IOManip function
 // ----------------------------------------------------------------------------


@@ -1242,5 +1545,4 @@ wxOutputStream& wxEndL(wxOutputStream& stream)
     return stream.Write(eol, wxStrlen(eol));
 }
 
     return stream.Write(eol, wxStrlen(eol));
 }
 

-#endif
-  // wxUSE_STREAMS
+#endif // wxUSE_STREAMS