the tile is assumed to be 256 in width
but as seen with unit-tiletest that is not always the case
==24170==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x63400001e808 at pc 0x558a6f505973 bp 0x7ffc0670e7d0 sp 0x7ffc0670e7c8
READ of size 8 at 0x63400001e808 thread T0 (kitbroker_002)
#0 0x558a6f505972 in DeltaGenerator::DeltaBitmapRow::initRow(unsigned int const*, unsigned int) Delta.hpp:129:36
#1 0x558a6f4fc318 in DeltaGenerator::DeltaData::DeltaData(unsigned int, unsigned char*, unsigned long, unsigned long, int, int, TileLocation const&, int, int) Delta.hpp:233:21
#2 0x558a6f4f8a22 in DeltaGenerator::createDelta(unsigned char*, unsigned long, unsigned long, int, int, int, int, TileLocation const&, std::vector<char, std::allocator<char> >&, unsigned int, bool) Delta.hpp:574:17
#3 0x558a6f4f2a35 in DeltaGenerator::compressOrDelta(unsigned char*, unsigned long, unsigned long, int, int, int, int, TileLocation const&, std::vector<char, std::allocator<char> >&, unsigned int, bool, bool, LibreOfficeKitTileMode) Delta.hpp:669:14
#4 0x558a6f41f300 in RenderTiles::doRender(std::shared_ptr<lok::Document>, DeltaGenerator&, TileCombined&, ThreadPool&, bool, std::function<void (unsigned char*, int, int, unsigned long, unsigned long, int, int, LibreOfficeKitTileMode)> const&, std::function<void (char const*, unsigned long)> const&, unsigned int, int, bool)::$_0::operator()() const /home/vmiklos/git/libreoffice/online-san/./common/RenderTiles.hpp:304:38
so just use the rle cache for the first 256 pixels
Signed-off-by: Caolán McNamara <caolan.mcnamara@collabora.com>
Change-Id: I8d34ea53bd20b69184e100b56017dfc0a904eaab
d3ecb6c95f