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Diffstat (limited to 'vcl/source/gdi/dibtools.cxx')
-rw-r--r--vcl/source/gdi/dibtools.cxx58
1 files changed, 43 insertions, 15 deletions
diff --git a/vcl/source/gdi/dibtools.cxx b/vcl/source/gdi/dibtools.cxx
index 7ef94634f904..cf3f68660513 100644
--- a/vcl/source/gdi/dibtools.cxx
+++ b/vcl/source/gdi/dibtools.cxx
@@ -328,6 +328,22 @@ bool ImplReadDIBPalette( SvStream& rIStm, BitmapWriteAccess& rAcc, bool bQuad )
return( rIStm.GetError() == 0UL );
}
+namespace
+{
+ sal_uInt8 SanitizePaletteIndex(sal_uInt8 nIndex, bool bHasPalette, sal_uInt16 nPaletteEntryCount)
+ {
+ if (bHasPalette && nIndex >= nPaletteEntryCount)
+ {
+ auto nSanitizedIndex = nIndex % nPaletteEntryCount;
+ SAL_WARN_IF(nIndex != nSanitizedIndex, "vcl", "invalid colormap index: "
+ << static_cast<unsigned int>(nIndex) << ", colormap len is: "
+ << nPaletteEntryCount);
+ nIndex = nSanitizedIndex;
+ }
+ return nIndex;
+ }
+}
+
bool ImplDecodeRLE( sal_uInt8* pBuffer, DIBV5Header& rHeader, BitmapWriteAccess& rAcc, bool bRLE4 )
{
Scanline pRLE = pBuffer;
@@ -339,6 +355,8 @@ bool ImplDecodeRLE( sal_uInt8* pBuffer, DIBV5Header& rHeader, BitmapWriteAccess&
sal_uLong nX = 0UL;
sal_uInt8 cTmp;
bool bEndDecoding = false;
+ const bool bHasPalette = rAcc.HasPalette();
+ const sal_uInt16 nPaletteEntryCount = rAcc.GetPaletteEntryCount();
do
{
@@ -364,10 +382,10 @@ bool ImplDecodeRLE( sal_uInt8* pBuffer, DIBV5Header& rHeader, BitmapWriteAccess&
cTmp = *pRLE++;
if( nX < nWidth )
- rAcc.SetPixelIndex( nY, nX++, cTmp >> 4 );
+ rAcc.SetPixelIndex(nY, nX++, SanitizePaletteIndex(cTmp >> 4, bHasPalette, nPaletteEntryCount));
if( nX < nWidth )
- rAcc.SetPixelIndex( nY, nX++, cTmp & 0x0f );
+ rAcc.SetPixelIndex(nY, nX++, SanitizePaletteIndex(cTmp & 0x0f, bHasPalette, nPaletteEntryCount));
}
if( nRunByte & 1 )
@@ -376,7 +394,7 @@ bool ImplDecodeRLE( sal_uInt8* pBuffer, DIBV5Header& rHeader, BitmapWriteAccess&
return false;
if( nX < nWidth )
- rAcc.SetPixelIndex( nY, nX++, *pRLE >> 4 );
+ rAcc.SetPixelIndex(nY, nX++, SanitizePaletteIndex(*pRLE >> 4, bHasPalette, nPaletteEntryCount));
pRLE++;
}
@@ -397,7 +415,7 @@ bool ImplDecodeRLE( sal_uInt8* pBuffer, DIBV5Header& rHeader, BitmapWriteAccess&
return false;
if( nX < nWidth )
- rAcc.SetPixelIndex( nY, nX++, *pRLE );
+ rAcc.SetPixelIndex(nY, nX++, SanitizePaletteIndex(*pRLE, bHasPalette, nPaletteEntryCount));
pRLE++;
}
@@ -444,19 +462,19 @@ bool ImplDecodeRLE( sal_uInt8* pBuffer, DIBV5Header& rHeader, BitmapWriteAccess&
for( sal_uLong i = 0UL; i < nRunByte; i++ )
{
if( nX < nWidth )
- rAcc.SetPixelIndex( nY, nX++, cTmp >> 4 );
+ rAcc.SetPixelIndex(nY, nX++, SanitizePaletteIndex(cTmp >> 4, bHasPalette, nPaletteEntryCount));
if( nX < nWidth )
- rAcc.SetPixelIndex( nY, nX++, cTmp & 0x0f );
+ rAcc.SetPixelIndex(nY, nX++, SanitizePaletteIndex(cTmp & 0x0f, bHasPalette, nPaletteEntryCount));
}
if( ( nCountByte & 1 ) && ( nX < nWidth ) )
- rAcc.SetPixelIndex( nY, nX++, cTmp >> 4 );
+ rAcc.SetPixelIndex(nY, nX++, SanitizePaletteIndex(cTmp >> 4, bHasPalette, nPaletteEntryCount));
}
else
{
for( sal_uLong i = 0UL; ( i < nCountByte ) && ( nX < nWidth ); i++ )
- rAcc.SetPixelIndex( nY, nX++, cTmp );
+ rAcc.SetPixelIndex(nY, nX++, SanitizePaletteIndex(cTmp, bHasPalette, nPaletteEntryCount));
}
}
}
@@ -478,10 +496,10 @@ bool ImplReadDIBBits(SvStream& rIStm, DIBV5Header& rHeader, BitmapWriteAccess& r
switch(rAcc.GetScanlineFormat())
{
case ScanlineFormat::N1BitMsbPal:
- case ScanlineFormat::N4BitMsnPal:
- case ScanlineFormat::N8BitPal:
case ScanlineFormat::N24BitTcBgr:
{
+ // we can't trust arbitrary-sourced index based formats to have correct indexes, so we exclude the pal formats
+ // from raw read and force checking their colormap indexes
bNative = ( ( static_cast< bool >(rAcc.IsBottomUp()) != bTopDown ) && !bRLE && !bTCMask && ( rAcc.GetScanlineSize() == nAlignedWidth ) );
break;
}
@@ -493,7 +511,7 @@ bool ImplReadDIBBits(SvStream& rIStm, DIBV5Header& rHeader, BitmapWriteAccess& r
}
// Read data
- if(bNative)
+ if (bNative)
{
if (nAlignedWidth
> std::numeric_limits<sal_Size>::max() / rHeader.nHeight)
@@ -517,7 +535,7 @@ bool ImplReadDIBBits(SvStream& rIStm, DIBV5Header& rHeader, BitmapWriteAccess& r
rIStm.ReadUInt32( nBMask );
}
- if(bRLE)
+ if (bRLE)
{
if(!rHeader.nSizeImage)
{
@@ -573,6 +591,9 @@ bool ImplReadDIBBits(SvStream& rIStm, DIBV5Header& rHeader, BitmapWriteAccess& r
case 4:
{
+ const bool bHasPalette = rAcc.HasPalette();
+ const sal_uInt16 nPaletteEntryCount = rAcc.GetPaletteEntryCount();
+
for( ; nCount--; nY += nI )
{
sal_uInt8 * pTmp = pBuf.get();
@@ -591,7 +612,8 @@ bool ImplReadDIBBits(SvStream& rIStm, DIBV5Header& rHeader, BitmapWriteAccess& r
cTmp = *pTmp++;
}
- rAcc.SetPixelIndex( nY, nX, (cTmp >> ( --nShift << 2UL ) ) & 0x0f);
+ auto nIndex = (cTmp >> ( --nShift << 2UL ) ) & 0x0f;
+ rAcc.SetPixelIndex(nY, nX, SanitizePaletteIndex(nIndex, bHasPalette, nPaletteEntryCount));
}
}
}
@@ -599,6 +621,9 @@ bool ImplReadDIBBits(SvStream& rIStm, DIBV5Header& rHeader, BitmapWriteAccess& r
case 8:
{
+ const bool bHasPalette = rAcc.HasPalette();
+ const sal_uInt16 nPaletteEntryCount = rAcc.GetPaletteEntryCount();
+
for( ; nCount--; nY += nI )
{
sal_uInt8 * pTmp = pBuf.get();
@@ -609,7 +634,10 @@ bool ImplReadDIBBits(SvStream& rIStm, DIBV5Header& rHeader, BitmapWriteAccess& r
}
for( long nX = 0L; nX < nWidth; nX++ )
- rAcc.SetPixelIndex( nY, nX, *pTmp++ );
+ {
+ auto nIndex = *pTmp++;
+ rAcc.SetPixelIndex(nY, nX, SanitizePaletteIndex(nIndex, bHasPalette, nPaletteEntryCount));
+ }
}
}
break;
@@ -894,7 +922,7 @@ bool ImplReadDIBBody( SvStream& rIStm, Bitmap& rBmp, AlphaMask* pBmpAlpha, sal_u
}
// read palette
- if(nColors)
+ if (nColors)
{
pAcc->SetPaletteEntryCount(nColors);
ImplReadDIBPalette(*pIStm, *pAcc, aHeader.nSize != DIBCOREHEADERSIZE);
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-24 17:53:37 +0000