flewkey/cuberite-2a
1
0
Fork 0
Code Releases Activity

Fixed overflow bug

Browse Source
This commit is contained in:
worktycho 2014-05-29 17:41:07 +01:00
parent f7777e8c75
commit 80fe19c0e2
1 changed files with 9 additions and 6 deletions

15
src/ChunkData.cpp

@ -333,25 +333,28 @@ cChunkData cChunkData::Copy(void) const
void cChunkData::CopyBlockTypes(BLOCKTYPE * a_Dest, size_t a_Idx, size_t a_Length) const void cChunkData::CopyBlockTypes(BLOCKTYPE * a_Dest, size_t a_Idx, size_t a_Length) const
{ {
// TODO: This code seems wrong. It always copies into a_Dest[i * SegmentLength], even when a_Idx > 0 size_t toskip = a_Idx;
for (size_t i = 0; i < NumSections; i++) for (size_t i = 0; i < NumSections; i++)
{ {
const size_t SegmentLength = SectionHeight * 16 * 16; const size_t SegmentLength = SectionHeight * 16 * 16;
if (a_Idx > 0) size_t startpos = 0;
if (toskip > 0)
{ {
a_Idx = std::max(a_Idx - a_Length, (size_t) 0); toskip = std::max(toskip - SegmentLength, (size_t) 0);
startpos = SegmentLength - toskip;
} }
if (a_Idx == 0) if (toskip == 0)
{ {
size_t ToCopy = std::min(SegmentLength, a_Length); size_t ToCopy = std::min(SegmentLength, a_Length);
a_Length -= ToCopy; a_Length -= ToCopy;
if (m_Sections[i] != NULL) if (m_Sections[i] != NULL)
{ {
memcpy(&a_Dest[i * SegmentLength], &m_Sections[i]->m_BlockTypes, sizeof(BLOCKTYPE) * ToCopy); memcpy(&a_Dest[(i * SegmentLength) - a_Idx], (&m_Sections[i]->m_BlockTypes) + startpos, sizeof(BLOCKTYPE) * (ToCopy - startpos));
} }
else else
{ {
memset(&a_Dest[i * SegmentLength], 0, sizeof(BLOCKTYPE) * ToCopy); memset(&a_Dest[(i * SegmentLength) - a_Idx], 0, sizeof(BLOCKTYPE) * (ToCopy - startpos));
} }
} }
} }