From a9a2485d6464928fcf1012e573f4b3b734238300 Mon Sep 17 00:00:00 2001
From: Francesco Montorsi <f18m_cpp217828@yahoo.it>
Date: Mon, 1 Jun 2009 13:56:41 +0000
Subject: [PATCH] fix loading ICO from socket stream: override OnSysTell and
 OnSysSeek rather than directly SeekO/I or TellO/I; in wxICOHandler only call
 SeekI() if we have a non-null seek offset

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@60856 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 include/wx/sckstrm.h   | 51 ++++++++++++++++++++++--------------------
 src/common/imagbmp.cpp |  8 +++----
 2 files changed, 31 insertions(+), 28 deletions(-)

diff --git a/include/wx/sckstrm.h b/include/wx/sckstrm.h
index 7018209199..c9c19f284b 100644
--- a/include/wx/sckstrm.h
+++ b/include/wx/sckstrm.h
@@ -19,38 +19,41 @@
 
 class WXDLLIMPEXP_NET wxSocketOutputStream : public wxOutputStream
 {
- public:
-  wxSocketOutputStream(wxSocketBase& s);
-  virtual ~wxSocketOutputStream();
+public:
+    wxSocketOutputStream(wxSocketBase& s);
+    virtual ~wxSocketOutputStream();
 
-  wxFileOffset SeekO( wxFileOffset WXUNUSED(pos), wxSeekMode WXUNUSED(mode) )
-    { return -1; }
-  wxFileOffset TellO() const
-    { return -1; }
+protected:
+    wxSocketBase *m_o_socket;
 
- protected:
-  wxSocketBase *m_o_socket;
+    size_t OnSysWrite(const void *buffer, size_t bufsize);
 
-  size_t OnSysWrite(const void *buffer, size_t bufsize);
+    // socket streams are both un-seekable and size-less streams:
+    wxFileOffset OnSysTell() const 
+        { return wxInvalidOffset; }
+    wxFileOffset OnSysSeek(wxFileOffset WXUNUSED(pos), wxSeekMode WXUNUSED(mode)) 
+        { return wxInvalidOffset; }
 
     wxDECLARE_NO_COPY_CLASS(wxSocketOutputStream);
 };
 
 class WXDLLIMPEXP_NET wxSocketInputStream : public wxInputStream
 {
- public:
-  wxSocketInputStream(wxSocketBase& s);
-  virtual ~wxSocketInputStream();
+public:
+    wxSocketInputStream(wxSocketBase& s);
+    virtual ~wxSocketInputStream();
 
-  wxFileOffset SeekI( wxFileOffset WXUNUSED(pos), wxSeekMode WXUNUSED(mode) )
-    { return -1; }
-  wxFileOffset TellI() const
-    { return -1; }
+protected:
+    wxSocketBase *m_i_socket;
 
- protected:
-  wxSocketBase *m_i_socket;
+    size_t OnSysRead(void *buffer, size_t bufsize);
 
-  size_t OnSysRead(void *buffer, size_t bufsize);
+    // socket streams are both un-seekable and size-less streams:
+
+    wxFileOffset OnSysTell() const 
+        { return wxInvalidOffset; }
+    wxFileOffset OnSysSeek(wxFileOffset WXUNUSED(pos), wxSeekMode WXUNUSED(mode)) 
+        { return wxInvalidOffset; }
 
     wxDECLARE_NO_COPY_CLASS(wxSocketInputStream);
 };
@@ -58,11 +61,11 @@ class WXDLLIMPEXP_NET wxSocketInputStream : public wxInputStream
 class WXDLLIMPEXP_NET wxSocketStream : public wxSocketInputStream,
                    public wxSocketOutputStream
 {
- public:
-  wxSocketStream(wxSocketBase& s);
-  virtual ~wxSocketStream();
+public:
+    wxSocketStream(wxSocketBase& s);
+    virtual ~wxSocketStream();
 
-  wxDECLARE_NO_COPY_CLASS(wxSocketStream);
+    wxDECLARE_NO_COPY_CLASS(wxSocketStream);
 };
 
 #endif
diff --git a/src/common/imagbmp.cpp b/src/common/imagbmp.cpp
index 9693a0d85e..388a0c8224 100644
--- a/src/common/imagbmp.cpp
+++ b/src/common/imagbmp.cpp
@@ -1280,11 +1280,11 @@ bool wxICOHandler::DoLoadFile(wxImage *image, wxInputStream& stream,
     int iSel = wxNOT_FOUND;
 
     // remember how many bytes we read from the stream:
-    wxFileOffset offset = sizeof(IconDir);
+    wxFileOffset alreadySeeked = sizeof(IconDir);
     
     for (unsigned int i = 0; i < nIcons; i++ )
     {
-        offset += stream.Read(pCurrentEntry, sizeof(ICONDIRENTRY)).LastRead();
+        alreadySeeked += stream.Read(pCurrentEntry, sizeof(ICONDIRENTRY)).LastRead();
         
         // bHeight and bColorCount are wxUint8
         if ( pCurrentEntry->bWidth >= wMax )
@@ -1322,8 +1322,8 @@ bool wxICOHandler::DoLoadFile(wxImage *image, wxInputStream& stream,
         
         // NOTE: seeking a positive amount in wxFromCurrent mode allows us to
         //       load even non-seekable streams (see wxInputStream::SeekI docs)!
-        if (stream.SeekI(wxUINT32_SWAP_ON_BE(pCurrentEntry->dwImageOffset) - offset, 
-                         wxFromCurrent) == wxInvalidOffset)
+        wxFileOffset offset = wxUINT32_SWAP_ON_BE(pCurrentEntry->dwImageOffset) - alreadySeeked;
+        if (offset != 0 && stream.SeekI(offset, wxFromCurrent) == wxInvalidOffset)
             return false;
         
         bResult = LoadDib(image, stream, true, IsBmp);
-- 
2.47.2