vcl/source/gdi/dibtools.cxx | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-)
New commits: commit 9d2c6fc2f0bd79ae5dbe3ca5d0bb34aeecfb1efd Author: Andras Timar <andras.ti...@collabora.com> AuthorDate: Thu Jan 6 23:01:29 2022 +0100 Commit: Miklos Vajna <vmik...@collabora.com> CommitDate: Fri Jan 7 08:25:16 2022 +0100 Backport the better fix of tdf#73523 from master Change-Id: Ica2cfea7d91bc4f30f83ec74064895d707ab9882 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/128088 Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoff...@gmail.com> Reviewed-by: Miklos Vajna <vmik...@collabora.com> diff --git a/vcl/source/gdi/dibtools.cxx b/vcl/source/gdi/dibtools.cxx index 949423a1f255..6a64f60549fa 100644 --- a/vcl/source/gdi/dibtools.cxx +++ b/vcl/source/gdi/dibtools.cxx @@ -249,8 +249,18 @@ bool ImplReadDIBInfoHeader(SvStream& rIStm, DIBV5Header& rHeader, bool& bTopDown readUInt32( rHeader.nV5ProfileSize ); readUInt32( rHeader.nV5Reserved ); + // Read color mask. An additional 12 bytes of color bitfields follow the info header (WinBMPv3-NT) + sal_uInt32 nColorMask = 0; + if (BITFIELDS == rHeader.nCompression && DIBINFOHEADERSIZE == rHeader.nSize) + { + rIStm.ReadUInt32( rHeader.nV5RedMask ); + rIStm.ReadUInt32( rHeader.nV5GreenMask ); + rIStm.ReadUInt32( rHeader.nV5BlueMask ); + nColorMask = 12; + } + // seek to EndPos - if (!checkSeek(rIStm, aStartPos + rHeader.nSize)) + if (!checkSeek(rIStm, aStartPos + rHeader.nSize + nColorMask)) return false; } @@ -533,13 +543,12 @@ bool ImplReadDIBBits(SvStream& rIStm, DIBV5Header& rHeader, BitmapWriteAccess& r } else { - // Read color mask. An additional 12 bytes of color bitfields follow the info header (WinBMPv3-NT) - if(bTCMask && BITFIELDS == rHeader.nCompression && DIBINFOHEADERSIZE == rHeader.nSize) - { - rIStm.ReadUInt32( nRMask ); - rIStm.ReadUInt32( nGMask ); - rIStm.ReadUInt32( nBMask ); - } + if (rHeader.nV5RedMask > 0) + nRMask = rHeader.nV5RedMask; + if (rHeader.nV5GreenMask > 0) + nGMask = rHeader.nV5GreenMask; + if (rHeader.nV5BlueMask > 0) + nBMask = rHeader.nV5BlueMask; const long nWidth(rHeader.nWidth); const long nHeight(rHeader.nHeight); @@ -910,7 +919,13 @@ bool ImplReadDIBBody(SvStream& rIStm, Bitmap& rBmp, AlphaMask* pBmpAlpha, sal_uL if (nOffset) { - pIStm->SeekRel(nOffset - (pIStm->Tell() - nStmPos)); + // It is problematic to seek backwards. We are at the + // end of BITMAPINFOHEADER or 12 bytes further in case + // of WinBMPv3-NT format. It is possible to seek forward + // though because a gap may be there. + sal_Int32 nSeekRel = nOffset - (pIStm->Tell() - nStmPos); + if (nSeekRel > 0) + pIStm->SeekRel(nSeekRel); } const sal_Int64 nBitsPerLine (static_cast<sal_Int64>(aHeader.nWidth) * static_cast<sal_Int64>(aHeader.nBitCount));