Re: Patch: add conversion from pg_wchar to multibyte

Hello, Ishii-san!

We've talked on PGCon that I've questions about mule to wchar
conversion. My questions about pg_mule2wchar_with_len function are
following. In these parts of code:
*
*
else if (IS_LCPRV1(*from) && len >= 3)
{
from++;
*to = *from++ << 16;
*to |= *from++;
len -= 3;
}

and

else if (IS_LCPRV2(*from) && len >= 4)
{
from++;
*to = *from++ << 16;
*to |= *from++ << 8;
*to |= *from++;
len -= 4;
}

we skip first character of original string. Are we able to restore it back
from pg_wchar?
Also in this part of code we're shifting first byte by 16 bits:

if (IS_LC1(*from) && len >= 2)
{
*to = *from++ << 16;
*to |= *from++;
len -= 2;
}
else if (IS_LCPRV1(*from) && len >= 3)
{
from++;
*to = *from++ << 16;
*to |= *from++;
len -= 3;
}

Why don't we shift it by 8 bits?
You can see my patch in this thread where I propose purely mechanical
changes in this function which make inverse conversion possible.

------
With best regards,
Alexander Korotkov.