winhelp: Fix LZ77 decompressor.

This commit is contained in:
Kirill K. Smirnov 2006-08-11 19:28:49 +04:00 committed by Alexandre Julliard
parent 4aaf1f0b9e
commit 27681bdfaf

View file

@ -1498,8 +1498,16 @@ static BYTE *HLPFILE_UncompressLZ77(BYTE *ptr, BYTE *end, BYTE *newptr)
int code = GET_USHORT(ptr, 0);
int len = 3 + (code >> 12);
int offset = code & 0xfff;
memcpy(newptr, newptr - offset - 1, len);
newptr += len;
/*
* We must copy byte-by-byte here. We cannot use memcpy nor
* memmove here. Just example:
* a[]={1,2,3,4,5,6,7,8,9,10}
* newptr=a+2;
* offset=1;
* We expect:
* {1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 11, 12}
*/
for (; len>0; len--, newptr++) *newptr = *(newptr-offset-1);
ptr += 2;
}
else *newptr++ = *ptr++;