bulk copy of latest physfs to our misc/libphysfs since this seems to fix an off-by-1 error reliably hit in readln read of 1 byte probably introduced in the addition of the buffered read. Whether this is excessive or whether libphysfs should even be maintained by us is another matter. But at least we shouldn't crash
/* BranchX86.c */
#include "BranchX86.h"
#define Test86MSByte(b) ((b) == 0 || (b) == 0xFF)
const Byte kMaskToAllowedStatus[8] = {1, 1, 1, 0, 1, 0, 0, 0};
const Byte kMaskToBitNumber[8] = {0, 1, 2, 2, 3, 3, 3, 3};
SizeT x86_Convert(Byte *buffer, SizeT endPos, UInt32 nowPos, UInt32 *prevMaskMix, int encoding)
{
SizeT bufferPos = 0, prevPosT;
UInt32 prevMask = *prevMaskMix & 0x7;
if (endPos < 5)
return 0;
nowPos += 5;
prevPosT = (SizeT)0 - 1;
for(;;)
{
Byte *p = buffer + bufferPos;
Byte *limit = buffer + endPos - 4;
for (; p < limit; p++)
if ((*p & 0xFE) == 0xE8)
break;
bufferPos = (SizeT)(p - buffer);
if (p >= limit)
break;
prevPosT = bufferPos - prevPosT;
if (prevPosT > 3)
prevMask = 0;
else
{
prevMask = (prevMask << ((int)prevPosT - 1)) & 0x7;
if (prevMask != 0)
{
Byte b = p[4 - kMaskToBitNumber[prevMask]];
if (!kMaskToAllowedStatus[prevMask] || Test86MSByte(b))
{
prevPosT = bufferPos;
prevMask = ((prevMask << 1) & 0x7) | 1;
bufferPos++;
continue;
}
}
}
prevPosT = bufferPos;
if (Test86MSByte(p[4]))
{
UInt32 src = ((UInt32)p[4] << 24) | ((UInt32)p[3] << 16) | ((UInt32)p[2] << 8) | ((UInt32)p[1]);
UInt32 dest;
for (;;)
{
Byte b;
int index;
if (encoding)
dest = (nowPos + (UInt32)bufferPos) + src;
else
dest = src - (nowPos + (UInt32)bufferPos);
if (prevMask == 0)
break;
index = kMaskToBitNumber[prevMask] * 8;
b = (Byte)(dest >> (24 - index));
if (!Test86MSByte(b))
break;
src = dest ^ ((1 << (32 - index)) - 1);
}
p[4] = (Byte)(~(((dest >> 24) & 1) - 1));
p[3] = (Byte)(dest >> 16);
p[2] = (Byte)(dest >> 8);
p[1] = (Byte)dest;
bufferPos += 5;
}
else
{
prevMask = ((prevMask << 1) & 0x7) | 1;
bufferPos++;
}
}
prevPosT = bufferPos - prevPosT;
*prevMaskMix = ((prevPosT > 3) ? 0 : ((prevMask << ((int)prevPosT - 1)) & 0x7));
return bufferPos;
}