Make code reading BMP files more robust.

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

diff --git a/src/common/gifdecod.cpp b/src/common/gifdecod.cpp
index 0a2dad27244465b6811980ccb722e872c247b656..b853ee97a987f11e9e4eee57b8292318e3927f11 100644 (file)
--- a/src/common/gifdecod.cpp
+++ b/src/common/gifdecod.cpp
@@ -19,15 +19,28 @@
 
 #ifndef WX_PRECOMP
     #include "wx/palette.h"
 
 #ifndef WX_PRECOMP
     #include "wx/palette.h"

+    #include "wx/intl.h"
+    #include "wx/log.h"

 #endif
 
 #include <stdlib.h>
 #include <string.h>
 #include "wx/gifdecod.h"
 #endif
 
 #include <stdlib.h>
 #include <string.h>
 #include "wx/gifdecod.h"

-#include "wx/ptr_scpd.h"
+#include "wx/scopedptr.h"

 #include "wx/scopeguard.h"
 
 #include "wx/scopeguard.h"
 

+enum
+{
+    GIF_MARKER_EXT       = '!', // 0x21
+    GIF_MARKER_SEP       = ',', // 0x2C
+    GIF_MARKER_ENDOFDATA = ';', // 0x3B
+
+    GIF_MARKER_EXT_GRAPHICS_CONTROL = 0xF9,
+    GIF_MARKER_EXT_COMMENT          = 0xFE,
+    GIF_MARKER_EXT_APP              = 0xFF
+};

 
 

+#define GetFrame(n)     ((GIFImage*)m_frames[n])

 
 //---------------------------------------------------------------------------
 // GIFImage
 
 //---------------------------------------------------------------------------
 // GIFImage


@@ -50,8 +63,9 @@ public:
     unsigned char *p;               // bitmap
     unsigned char *pal;             // palette
     unsigned int ncolours;          // number of colours
     unsigned char *p;               // bitmap
     unsigned char *pal;             // palette
     unsigned int ncolours;          // number of colours

+    wxString comment;

 
 

-    DECLARE_NO_COPY_CLASS(GIFImage)
+    wxDECLARE_NO_COPY_CLASS(GIFImage);

 };
 
 wxDECLARE_SCOPED_PTR(GIFImage, GIFImagePtr)
 };
 
 wxDECLARE_SCOPED_PTR(GIFImage, GIFImagePtr)


@@ -124,7 +138,7 @@ bool wxGIFDecoder::ConvertToImage(unsigned int frame, wxImage *image) const
     image->Create(sz.GetWidth(), sz.GetHeight());
     image->SetType(wxBITMAP_TYPE_GIF);
 
     image->Create(sz.GetWidth(), sz.GetHeight());
     image->SetType(wxBITMAP_TYPE_GIF);
 

-    if (!image->Ok())
+    if (!image->IsOk())

         return false;
 
     pal = GetPalette(frame);
         return false;
 
     pal = GetPalette(frame);


@@ -178,6 +192,12 @@ bool wxGIFDecoder::ConvertToImage(unsigned int frame, wxImage *image) const
         *(dst++) = pal[3 * (*src) + 2];
     }
 
         *(dst++) = pal[3 * (*src) + 2];
     }
 

+    wxString comment = GetFrame(frame)->comment;
+    if ( !comment.empty() )
+    {
+        image->SetOption(wxIMAGE_OPTION_GIF_COMMENT, comment);
+    }
+

     return true;
 }
 
     return true;
 }
 


@@ -186,9 +206,6 @@ bool wxGIFDecoder::ConvertToImage(unsigned int frame, wxImage *image) const
 // Data accessors
 //---------------------------------------------------------------------------
 
 // Data accessors
 //---------------------------------------------------------------------------
 

-#define GetFrame(n)     ((GIFImage*)m_frames[n])
-
-

 // Get data for current frame
 
 wxSize wxGIFDecoder::GetFrameSize(unsigned int frame) const
 // Get data for current frame
 
 wxSize wxGIFDecoder::GetFrameSize(unsigned int frame) const


@@ -252,7 +269,7 @@ int wxGIFDecoder::getcode(wxInputStream& stream, int bits, int ab_fin)
         // if no bytes left in this block, read the next block
         if (m_restbyte == 0)
         {
         // if no bytes left in this block, read the next block
         if (m_restbyte == 0)
         {

-            m_restbyte = (unsigned char)stream.GetC();
+            m_restbyte = stream.GetC();

 
             /* Some encoders are a bit broken: instead of issuing
              * an end-of-image symbol (ab_fin) they come up with
 
             /* Some encoders are a bit broken: instead of issuing
              * an end-of-image symbol (ab_fin) they come up with


@@ -337,7 +354,7 @@ wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int interl, int bits)
     ab_clr = (1 << bits);
     ab_fin = (1 << bits) + 1;
 
     ab_clr = (1 << bits);
     ab_fin = (1 << bits) + 1;
 

-    // these will change through the decompression proccess
+    // these will change through the decompression process

     ab_bits  = bits + 1;
     ab_free  = (1 << bits) + 2;
     ab_max   = (1 << ab_bits) - 1;
     ab_bits  = bits + 1;
     ab_free  = (1 << bits) + 2;
     ab_max   = (1 << ab_bits) - 1;


@@ -573,16 +590,13 @@ as an End of Information itself)
 // CanRead:
 //  Returns true if the file looks like a valid GIF, false otherwise.
 //
 // CanRead:
 //  Returns true if the file looks like a valid GIF, false otherwise.
 //

-bool wxGIFDecoder::CanRead(wxInputStream &stream) const
+bool wxGIFDecoder::DoCanRead(wxInputStream &stream) const

 {
     unsigned char buf[3];
 
     if ( !stream.Read(buf, WXSIZEOF(buf)) )
         return false;
 
 {
     unsigned char buf[3];
 
     if ( !stream.Read(buf, WXSIZEOF(buf)) )
         return false;
 

-    if (stream.SeekI(-(wxFileOffset)WXSIZEOF(buf), wxFromCurrent) == wxInvalidOffset)
-        return false;       // this happens e.g. for non-seekable streams
-

     return memcmp(buf, "GIF", WXSIZEOF(buf)) == 0;
 }
 
     return memcmp(buf, "GIF", WXSIZEOF(buf)) == 0;
 }
 


@@ -664,15 +678,16 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
     int transparent = -1;
     disposal = wxANIM_UNSPECIFIED;
     delay = -1;
     int transparent = -1;
     disposal = wxANIM_UNSPECIFIED;
     delay = -1;

+    wxString comment;

 
     bool done = false;
     while (!done)
     {
 
     bool done = false;
     while (!done)
     {

-        type = (unsigned char)stream.GetC();
+        type = stream.GetC();

 
         /*
         If the end of file has been reached (or an error) and a ";"
 
         /*
         If the end of file has been reached (or an error) and a ";"

-        (0x3B) hasn't been encountered yet, exit the loop. (Without this
+        (GIF_MARKER_ENDOFDATA) hasn't been encountered yet, exit the loop. (Without this

         check the while loop would loop endlessly.) Later on, in the next while
         loop, the file will be treated as being truncated (But still
         be decoded as far as possible). returning wxGIF_TRUNCATED is not
         check the while loop would loop endlessly.) Later on, in the next while
         loop, the file will be treated as being truncated (But still
         be decoded as far as possible). returning wxGIF_TRUNCATED is not


@@ -687,129 +702,179 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
             break; // Alternative : "return wxGIF_INVFORMAT;"
         }
 
             break; // Alternative : "return wxGIF_INVFORMAT;"
         }
 

-        // end of data?
-        if (type == 0x3B)
+        switch (type)

         {
         {

-            done = true;
-        }
-        else
-        // extension block?
-        if (type == 0x21)
-        {
-            if (((unsigned char)stream.GetC()) == 0xF9)
-            // graphics control extension, parse it
-            {
-                static const unsigned int gceSize = 6;
-                stream.Read(buf, gceSize);
-                if (stream.LastRead() != gceSize)
+            case GIF_MARKER_ENDOFDATA:
+                done = true;
+                break;
+            case GIF_MARKER_EXT:
+                switch (stream.GetC())

                 {
                 {

-                    Destroy();
-                    return wxGIF_INVFORMAT;
-                }
+                    case GIF_MARKER_EXT_GRAPHICS_CONTROL:
+                    {
+                        // graphics control extension, parse it
+
+                        static const unsigned int gceSize = 6;
+                        stream.Read(buf, gceSize);
+                        if (stream.LastRead() != gceSize)
+                        {
+                            Destroy();
+                            return wxGIF_INVFORMAT;
+                        }

 
 

-                // read delay and convert from 1/100 of a second to ms
-                delay = 10 * (buf[2] + 256 * buf[3]);
+                        // read delay and convert from 1/100 of a second to ms
+                        delay = 10 * (buf[2] + 256 * buf[3]);

 
 

-                // read transparent colour index, if used
-                transparent = buf[1] & 0x01 ? buf[4] : -1;
+                        // read transparent colour index, if used
+                        transparent = buf[1] & 0x01 ? buf[4] : -1;

 
 

-                // read disposal method
-                disposal = (wxAnimationDisposal)(((buf[1] & 0x1C) >> 2) - 1);
-            }
-            else
-            // other extension, skip
-            {
-                while ((i = (unsigned char)stream.GetC()) != 0)
-                {
-                    if (stream.Eof() || (stream.LastRead() == 0) ||
-                        stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+                        // read disposal method
+                        disposal = (wxAnimationDisposal)(((buf[1] & 0x1C) >> 2) - 1);
+                        break;
+                    }
+                    case GIF_MARKER_EXT_COMMENT:

                     {
                     {

-                        done = true;
+                        int len = stream.GetC();
+                        while (len)
+                        {
+                            if ( stream.Eof() )
+                            {
+                                done = true;
+                                break;
+                            }
+
+                            wxCharBuffer charbuf(len);
+                            stream.Read(charbuf.data(), len);
+                            if ( (int) stream.LastRead() != len )
+                            {
+                                done = true;
+                                break;
+                            }
+
+                            comment += wxConvertMB2WX(charbuf.data());
+
+                            len = stream.GetC();
+                        }
+

                         break;
                     }
                         break;
                     }

+                    default:
+                        // other extension, skip
+                        while ((i = stream.GetC()) != 0)
+                        {
+                            if (stream.Eof() || (stream.LastRead() == 0) ||
+                                stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+                            {
+                                done = true;
+                                break;
+                            }
+                        }
+                        break;

                 }
                 }

-            }
-        }
-        else
-        // image descriptor block?
-        if (type == 0x2C)
-        {
-            // allocate memory for IMAGEN struct
-            GIFImagePtr pimg(new GIFImage());
+                break;
+            case GIF_MARKER_SEP:
+            {
+                // allocate memory for IMAGEN struct
+                GIFImagePtr pimg(new GIFImage());

 
 

-            wxScopeGuard guardDestroy = wxMakeObjGuard(*this, &wxGIFDecoder::Destroy);
+                wxScopeGuard guardDestroy = wxMakeObjGuard(*this, &wxGIFDecoder::Destroy);

 
 

-            if ( !pimg.get() )
-                return wxGIF_MEMERR;
+                if ( !pimg.get() )
+                    return wxGIF_MEMERR;

 
 

-            // fill in the data
-            static const unsigned int idbSize = (2 + 2 + 2 + 2 + 1);
-            stream.Read(buf, idbSize);
-            if (stream.LastRead() != idbSize)
-                return wxGIF_INVFORMAT;
+                // fill in the data
+                static const unsigned int idbSize = (2 + 2 + 2 + 2 + 1);
+                stream.Read(buf, idbSize);
+                if (stream.LastRead() != idbSize)
+                    return wxGIF_INVFORMAT;

 
 

-            pimg->left = buf[0] + 256 * buf[1];
-            pimg->top = buf[2] + 256 * buf[3];
-/*
-            pimg->left = buf[4] + 256 * buf[5];
-            pimg->top = buf[4] + 256 * buf[5];
-*/
-            pimg->w = buf[4] + 256 * buf[5];
-            pimg->h = buf[6] + 256 * buf[7];
+                pimg->comment = comment;
+                comment.clear();
+                pimg->left = buf[0] + 256 * buf[1];
+                pimg->top = buf[2] + 256 * buf[3];
+    /*
+                pimg->left = buf[4] + 256 * buf[5];
+                pimg->top = buf[4] + 256 * buf[5];
+    */
+                pimg->w = buf[4] + 256 * buf[5];
+                pimg->h = buf[6] + 256 * buf[7];
+
+                if ( anim )
+                {
+                    // some GIF images specify incorrect animation size but we can
+                    // still open them if we fix up the animation size, see #9465
+                    if ( m_nFrames == 0 )
+                    {
+                        if ( pimg->w > (unsigned)m_szAnimation.x )
+                            m_szAnimation.x = pimg->w;
+                        if ( pimg->h > (unsigned)m_szAnimation.y )
+                            m_szAnimation.y = pimg->h;
+                    }
+                    else // subsequent frames
+                    {
+                        // check that we have valid size
+                        if ( (!pimg->w || pimg->w > (unsigned)m_szAnimation.x) ||
+                                (!pimg->h || pimg->h > (unsigned)m_szAnimation.y) )
+                        {
+                            wxLogError(_("Incorrect GIF frame size (%u, %d) for "
+                                         "the frame #%u"),
+                                       pimg->w, pimg->h, m_nFrames);
+                            return wxGIF_INVFORMAT;
+                        }
+                    }
+                }

 
 

-            if ( anim && ((pimg->w == 0) || (pimg->w > (unsigned int)m_szAnimation.GetWidth()) ||
-                  (pimg->h == 0) || (pimg->h > (unsigned int)m_szAnimation.GetHeight())) )
-                return wxGIF_INVFORMAT;
+                interl = ((buf[8] & 0x40)? 1 : 0);
+                size = pimg->w * pimg->h;

 
 

-            interl = ((buf[8] & 0x40)? 1 : 0);
-            size = pimg->w * pimg->h;
+                pimg->transparent = transparent;
+                pimg->disposal = disposal;
+                pimg->delay = delay;

 
 

-            pimg->transparent = transparent;
-            pimg->disposal = disposal;
-            pimg->delay = delay;
+                // allocate memory for image and palette
+                pimg->p   = (unsigned char *) malloc((unsigned int)size);
+                pimg->pal = (unsigned char *) malloc(768);

 
 

-            // allocate memory for image and palette
-            pimg->p   = (unsigned char *) malloc((unsigned int)size);
-            pimg->pal = (unsigned char *) malloc(768);
+                if ((!pimg->p) || (!pimg->pal))
+                    return wxGIF_MEMERR;

 
 

-            if ((!pimg->p) || (!pimg->pal))
-                return wxGIF_MEMERR;
+                // load local color map if available, else use global map
+                if ((buf[8] & 0x80) == 0x80)
+                {
+                    unsigned int local_ncolors = 2 << (buf[8] & 0x07);
+                    unsigned int numBytes = 3 * local_ncolors;
+                    stream.Read(pimg->pal, numBytes);
+                    pimg->ncolours = local_ncolors;
+                    if (stream.LastRead() != numBytes)
+                        return wxGIF_INVFORMAT;
+                }
+                else
+                {
+                    memcpy(pimg->pal, pal, 768);
+                    pimg->ncolours = global_ncolors;
+                }

 
 

-            // load local color map if available, else use global map
-            if ((buf[8] & 0x80) == 0x80)
-            {
-                unsigned int local_ncolors = 2 << (buf[8] & 0x07);
-                unsigned int numBytes = 3 * local_ncolors;
-                stream.Read(pimg->pal, numBytes);
-                pimg->ncolours = local_ncolors;
-                if (stream.LastRead() != numBytes)
+                // get initial code size from first byte in raster data
+                bits = stream.GetC();
+                if (bits == 0)

                     return wxGIF_INVFORMAT;
                     return wxGIF_INVFORMAT;

-            }
-            else
-            {
-                memcpy(pimg->pal, pal, 768);
-                pimg->ncolours = global_ncolors;
-            }
-
-            // get initial code size from first byte in raster data
-            bits = (unsigned char)stream.GetC();
-            if (bits == 0)
-                return wxGIF_INVFORMAT;

 
 

-            // decode image
-            wxGIFErrorCode result = dgif(stream, pimg.get(), interl, bits);
-            if (result != wxGIF_OK)
-                return result;
+                // decode image
+                wxGIFErrorCode result = dgif(stream, pimg.get(), interl, bits);
+                if (result != wxGIF_OK)
+                    return result;

 
 

-            guardDestroy.Dismiss();
+                guardDestroy.Dismiss();

 
 

-            // add the image to our frame array
-            m_frames.Add(pimg.release());
-            m_nFrames++;
+                // add the image to our frame array
+                m_frames.Add(pimg.release());
+                m_nFrames++;

 
 

-            // if this is not an animated GIF, exit after first image
-            if (!anim)
-                done = true;
+                // if this is not an animated GIF, exit after first image
+                if (!anim)
+                    done = true;
+                break;
+            }

         }
     }
 
         }
     }
 


@@ -820,75 +885,80 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
     }
 
     // try to read to the end of the stream
     }
 
     // try to read to the end of the stream

-    while (type != 0x3B)
+    while (type != GIF_MARKER_ENDOFDATA)

     {
         if (!stream.IsOk())
             return wxGIF_TRUNCATED;
 
     {
         if (!stream.IsOk())
             return wxGIF_TRUNCATED;
 

-        type = (unsigned char)stream.GetC();
+        type = stream.GetC();

 
 

-        if (type == 0x21)
+        switch (type)

         {
         {

-            // extension type
-            (void) stream.GetC();
+            case GIF_MARKER_EXT:
+                // extension type
+                (void) stream.GetC();

 
 

-            // skip all data
-            while ((i = (unsigned char)stream.GetC()) != 0)
-            {
-                if (stream.Eof() || (stream.LastRead() == 0) ||
-                    stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+                // skip all data
+                while ((i = stream.GetC()) != 0)

                 {
                 {

-                    Destroy();
-                    return wxGIF_INVFORMAT;
+                    if (stream.Eof() || (stream.LastRead() == 0) ||
+                        stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+                    {
+                        Destroy();
+                        return wxGIF_INVFORMAT;
+                    }

                 }
                 }

-            }
-        }
-        else if (type == 0x2C)
-        {
-            // image descriptor block
-            static const unsigned int idbSize = (2 + 2 + 2 + 2 + 1);
-            stream.Read(buf, idbSize);
-            if (stream.LastRead() != idbSize)
-            {
-                Destroy();
-                return wxGIF_INVFORMAT;
-            }
-
-            // local color map
-            if ((buf[8] & 0x80) == 0x80)
+                break;
+            case GIF_MARKER_SEP:

             {
             {

-                unsigned int local_ncolors = 2 << (buf[8] & 0x07);
-                wxFileOffset numBytes = 3 * local_ncolors;
-                if (stream.SeekI(numBytes, wxFromCurrent) == wxInvalidOffset)
+                // image descriptor block
+                static const unsigned int idbSize = (2 + 2 + 2 + 2 + 1);
+                stream.Read(buf, idbSize);
+                if (stream.LastRead() != idbSize)

                 {
                     Destroy();
                     return wxGIF_INVFORMAT;
                 }
                 {
                     Destroy();
                     return wxGIF_INVFORMAT;
                 }

-            }

 
 

-            // initial code size
-            (void) stream.GetC();
-            if (stream.Eof() || (stream.LastRead() == 0))
-            {
-                Destroy();
-                return wxGIF_INVFORMAT;
-            }
+                // local color map
+                if ((buf[8] & 0x80) == 0x80)
+                {
+                    unsigned int local_ncolors = 2 << (buf[8] & 0x07);
+                    wxFileOffset numBytes = 3 * local_ncolors;
+                    if (stream.SeekI(numBytes, wxFromCurrent) == wxInvalidOffset)
+                    {
+                        Destroy();
+                        return wxGIF_INVFORMAT;
+                    }
+                }

 
 

-            // skip all data
-            while ((i = (unsigned char)stream.GetC()) != 0)
-            {
-                if (stream.Eof() || (stream.LastRead() == 0) ||
-                    stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+                // initial code size
+                (void) stream.GetC();
+                if (stream.Eof() || (stream.LastRead() == 0))

                 {
                     Destroy();
                     return wxGIF_INVFORMAT;
                 }
                 {
                     Destroy();
                     return wxGIF_INVFORMAT;
                 }

+
+                // skip all data
+                while ((i = stream.GetC()) != 0)
+                {
+                    if (stream.Eof() || (stream.LastRead() == 0) ||
+                        stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+                    {
+                        Destroy();
+                        return wxGIF_INVFORMAT;
+                    }
+                }
+                break;

             }
             }

-        }
-        else if ((type != 0x3B) && (type != 00)) // testing
-        {
-            // images are OK, but couldn't read to the end of the stream
-            return wxGIF_TRUNCATED;
+            default:
+                if ((type != GIF_MARKER_ENDOFDATA) && (type != 00)) // testing
+                {
+                    // images are OK, but couldn't read to the end of the stream
+                    return wxGIF_TRUNCATED;
+                }
+                break;

         }
     }
 
         }
     }