[Libreoffice-commits] core.git: vcl/source

[Ashod Nakashian]

 vcl/source/gdi/bitmap3.cxx |   13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

New commits:
commit c91bfb9ac7d110c5dca0ea34ec0e1668a985b34c
Author: Ashod Nakashian <ashodnakashian at yahoo.com>
Date:   Mon Feb 23 22:33:27 2015 -0500

    Fix crash while scaling large bitmaps.
    
    Fast bitmap scaling overflowed the LUT used by the nearest-neighbor algorithm.
    When a bitmap has 46k pixel on a side and is enlarged, the scaling code
    overflows the 32-bit long, resulting in negative indexes, which then segfaults.
    
    This isn't as rare as it sounds. At least in web-view in writer the border/shadow
    bitmap is as long as the document (which is an issue in its own right,)
    which can overflow for large documents during scaling and segfault.
    
    Change-Id: I1ccf73d02469f6601a9a7e67b30524cb497cf6bc
    Reviewed-on: https://gerrit.libreoffice.org/14597
    Reviewed-by: Caolán McNamara <caolanm at redhat.com>
    Tested-by: Caolán McNamara <caolanm at redhat.com>

diff --git a/vcl/source/gdi/bitmap3.cxx b/vcl/source/gdi/bitmap3.cxx
index 2bd586f..bfd25a6 100644
--- a/vcl/source/gdi/bitmap3.cxx
+++ b/vcl/source/gdi/bitmap3.cxx
@@ -1075,18 +1075,19 @@ bool Bitmap::ImplScaleFast( const double& rScaleX, const double& rScaleY )
                 const long nScanlineSize = pWriteAcc->GetScanlineSize();
                 const long nNewWidth1 = nNewWidth - 1L;
                 const long nNewHeight1 = nNewHeight - 1L;
-                const long nWidth = pReadAcc->Width();
-                const long nHeight = pReadAcc->Height();
-                boost::scoped_array<long> pLutX(new long[ nNewWidth ]);
-                boost::scoped_array<long> pLutY(new long[ nNewHeight ]);
 
                 if( nNewWidth1 && nNewHeight1 )
                 {
+                    const double nWidth = pReadAcc->Width();
+                    const double nHeight = pReadAcc->Height();
+                    boost::scoped_array<long> pLutX(new long[ nNewWidth ]);
+                    boost::scoped_array<long> pLutY(new long[ nNewHeight ]);
+
                     for( long nX = 0L; nX < nNewWidth; nX++ )
-                        pLutX[ nX ] = nX * nWidth / nNewWidth;
+                        pLutX[ nX ] = long(nX * nWidth / nNewWidth);
 
                     for( long nY = 0L; nY < nNewHeight; nY++ )
-                        pLutY[ nY ] = nY * nHeight / nNewHeight;
+                        pLutY[ nY ] = long(nY * nHeight / nNewHeight);
 
                     long nActY = 0L;
                     while( nActY < nNewHeight )