[lz4f] Skip memcpy() on empty dictionary

This commit is contained in:
Nick Terrell 2018-01-05 14:30:49 -08:00
parent 506ae9c333
commit c2dd686e96

View File

@ -1631,7 +1631,8 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
if (dctx->tmpOutSize > 64 KB) copySize = 0;
if (copySize > preserveSize) copySize = preserveSize;
memcpy(dctx->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize);
if (copySize > 0)
memcpy(dctx->tmpOutBuffer + preserveSize - copySize, oldDictEnd - copySize, copySize);
dctx->dict = dctx->tmpOutBuffer;
dctx->dictSize = preserveSize + dctx->tmpOutStart;
@ -1639,7 +1640,8 @@ size_t LZ4F_decompress(LZ4F_dctx* dctx,
const BYTE* const oldDictEnd = dctx->dict + dctx->dictSize;
size_t const newDictSize = MIN(dctx->dictSize, 64 KB);
memcpy(dctx->tmpOutBuffer, oldDictEnd - newDictSize, newDictSize);
if (newDictSize > 0)
memcpy(dctx->tmpOutBuffer, oldDictEnd - newDictSize, newDictSize);
dctx->dict = dctx->tmpOutBuffer;
dctx->dictSize = newDictSize;