diff options
| -rw-r--r-- | vcl/source/gdi/pngread.cxx | 43 |
1 files changed, 38 insertions, 5 deletions
diff --git a/vcl/source/gdi/pngread.cxx b/vcl/source/gdi/pngread.cxx index 377d41be6df6..e6c9abea5e1c 100644 --- a/vcl/source/gdi/pngread.cxx +++ b/vcl/source/gdi/pngread.cxx @@ -1122,6 +1122,37 @@ void PNGReaderImpl::ImplApplyFilter() memcpy( mpScanPrior, mpInflateInBuf, mnScansize ); } +namespace +{ + sal_uInt8 SanitizePaletteIndex(sal_uInt8 nIndex, sal_uInt16 nPaletteEntryCount) + { + if (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; + } + + void SanitizePaletteIndexes(sal_uInt8* pEntries, int nLen, BitmapWriteAccess* pAcc) + { + sal_uInt16 nPaletteEntryCount = pAcc->GetPaletteEntryCount(); + for (int nX = 0; nX < nLen; ++nX) + { + if (pEntries[nX] >= nPaletteEntryCount) + { + SAL_WARN("vcl.gdi", "invalid colormap index: " + << static_cast<unsigned int>(pEntries[nX]) << ", colormap len is: " + << nPaletteEntryCount); + pEntries[nX] = pEntries[nX] % nPaletteEntryCount; + } + } + } +} + // ImplDrawScanlines draws the complete Scanline (nY) into the target bitmap // In interlace mode the parameter nXStart and nXAdd append to the currently used pass @@ -1137,7 +1168,7 @@ void PNGReaderImpl::ImplDrawScanline( sal_uInt32 nXStart, sal_uInt32 nXAdd ) // => TODO; also do this for nX here instead of in the ImplSet*Pixel() methods const sal_uInt32 nY = mnYpos >> mnPreviewShift; - const sal_uInt8* pTmp = mpInflateInBuf + 1; + sal_uInt8* pTmp = mpInflateInBuf + 1; if ( mpAcc->HasPalette() ) // alphachannel is not allowed by pictures including palette entries { switch ( mpAcc->GetBitCount() ) @@ -1304,6 +1335,8 @@ void PNGReaderImpl::ImplDrawScanline( sal_uInt32 nXStart, sal_uInt32 nXAdd ) if( nXAdd == 1 && mnPreviewShift == 0 ) // copy raw line data if possible { int nLineBytes = maOrigSize.Width(); + if (mbPalette) + SanitizePaletteIndexes(pTmp, nLineBytes, mpAcc); mpAcc->CopyScanline( nY, pTmp, ScanlineFormat::N8BitPal, nLineBytes ); } else @@ -1592,7 +1625,7 @@ void PNGReaderImpl::ImplSetPixel( sal_uInt32 nY, sal_uInt32 nX, sal_uInt8 nPalIn return; nX >>= mnPreviewShift; - mpAcc->SetPixelIndex( nY, nX, nPalIndex ); + mpAcc->SetPixelIndex(nY, nX, SanitizePaletteIndex(nPalIndex, mpAcc->GetPaletteEntryCount())); } void PNGReaderImpl::ImplSetTranspPixel( sal_uInt32 nY, sal_uInt32 nX, const BitmapColor& rBitmapColor, bool bTrans ) @@ -1618,8 +1651,8 @@ void PNGReaderImpl::ImplSetAlphaPixel( sal_uInt32 nY, sal_uInt32 nX, return; nX >>= mnPreviewShift; - mpAcc->SetPixelIndex( nY, nX, nPalIndex ); - mpMaskAcc->SetPixelIndex( nY, nX, ~nAlpha ); + mpAcc->SetPixelIndex(nY, nX, SanitizePaletteIndex(nPalIndex, mpAcc->GetPaletteEntryCount())); + mpMaskAcc->SetPixel(nY, nX, BitmapColor(~nAlpha)); } void PNGReaderImpl::ImplSetAlphaPixel( sal_uInt32 nY, sal_uInt32 nX, @@ -1633,7 +1666,7 @@ void PNGReaderImpl::ImplSetAlphaPixel( sal_uInt32 nY, sal_uInt32 nX, mpAcc->SetPixel( nY, nX, rBitmapColor ); if (!mpMaskAcc) return; - mpMaskAcc->SetPixelIndex( nY, nX, ~nAlpha ); + mpMaskAcc->SetPixel(nY, nX, BitmapColor(~nAlpha)); } sal_uInt32 PNGReaderImpl::ImplReadsal_uInt32() |