bug#9318: 23.3.50; The first call of encode-coding-region() returns wrong result

[Kazuhiro Ito <kzhr@d1.dion.ne.jp>]

> > > I think relocation of buffer may cause the problem.
> > 
> > Does that help?
> 
> Andreas' patch resolved the problem partially.  It resolved the problem on
> NetBSD with '-O0' CFLAGS, but failed on NetBSD with '-O2' and Windows.
> 
> I confirmed that adding the protection of coding->dst_object to
> Andreas' patch resolved the problem on NetBSD with '-O2' but not on
> Windows.  I don't know whether it is incorrect way or is not enough.

I noticed char_charset() could cause relocation of buffers because it
could call encode_char().  I confirmed similar changes to callers of
char_charset() fixed my problem (without the protection of
coding->dst_object).


SUMMARY OF THE PROBLEM:
In encode_coding_XXX(), calling encode_char() could cause relocation
of buffers.  char_charset(), ENCODE_ISO_CHARACTER and ENCODE_CHAR
could also cause relocation because they could call encode_char().
After using of them, coding->destination, dst, dst_end should be
updated as needed.

-- 
Kazuhiro Ito