relaxed ReadGIF error checking as per review

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@36618 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
David Surovell
2006-01-01 20:19:13 +00:00
parent 80b1853f9e
commit 295dec28c3

View File

@@ -675,8 +675,7 @@ int wxGIFDecoder::ReadGIF()
m_screenw = buf[0] + 256 * buf[1];
m_screenh = buf[2] + 256 * buf[3];
const int maxScreenSize = 4 << 10;
if ((m_screenw <= 0) || (m_screenw > maxScreenSize) || (m_screenh <= 0) || (m_screenh > maxScreenSize))
if ((m_screenw == 0) || (m_screenh == 0))
{
return wxGIF_INVFORMAT;
}
@@ -803,7 +802,7 @@ int wxGIFDecoder::ReadGIF()
pimg->w = buf[4] + 256 * buf[5];
pimg->h = buf[6] + 256 * buf[7];
if ((pimg->w <= 0) || (pimg->w > maxScreenSize) || (pimg->h <= 0) || (pimg->h > maxScreenSize))
if ((pimg->w == 0) || (pimg->w > m_screenw) || (pimg->h == 0) || (pimg->h > m_screenh))
{
Destroy();
return wxGIF_INVFORMAT;
@@ -835,9 +834,8 @@ int wxGIFDecoder::ReadGIF()
{
ncolors = 2 << (buf[8] & 0x07);
size_t numBytes = 3 * ncolors;
if (numBytes > 0)
m_f->Read(pimg->pal, numBytes);
if ((numBytes <= 0) || (m_f->LastRead() != numBytes))
m_f->Read(pimg->pal, numBytes);
if (m_f->LastRead() != numBytes)
{
Destroy();
return wxGIF_INVFORMAT;
@@ -916,12 +914,6 @@ int wxGIFDecoder::ReadGIF()
if ((buf[8] & 0x80) == 0x80)
{
ncolors = 2 << (buf[8] & 0x07);
if (ncolors <= 0)
{
Destroy();
return wxGIF_INVFORMAT;
}
wxFileOffset pos = m_f->TellI();
wxFileOffset numBytes = 3 * ncolors;
m_f->SeekI(numBytes, wxFromCurrent);