bug#20109: Incompatible API change in 2.0 series for string port encoding

[Mark H Weaver <mhw@netris.org>]

David Kastrup <dak@gnu.org> writes:

> Mark H Weaver <mhw@netris.org> writes:
>
>> This hack of giving Guile a buffer containing UTF-8, but claiming that
>> it is Latin-1, is not good.  It will cause Guile to see non-ASCII
>> characters as garbage.
>
> For one thing we are talking about an external file here that is mainly
> parsed by LilyPond.  LilyPond provides sensible pinpointing of UTF-8
> encoding errors, something which GUILE cannot do with its UTF-8
> representation since it has no transparent or reproducible
> representation of bad bytes.  Emacs uses overlong encodings for 0-127 to
> represent badly encoded bytes (which includes any overlong sequences) in
> the range 128-255, making 128-255 encode as patterns 0xc0 0x80 to 0xc1
> 0xbf.

I intend to add a similar mechanism to Guile, but it is not yet done.

>> However, if you insist on doing this, I would
>> suggest using a bytevector input port instead, like this: (untested)
>>
>>   char *buf = c_str ();
>>   SCM bv = scm_c_make_bytevector (strlen (buf) + 1);
>>   strcpy (SCM_BYTEVECTOR_CONTENTS (bv), buf);
>>   str_port_ = scm_open_bytevector_input_port (bv, SCM_UNDEFINED);
>
> dak@lola:/usr/local/tmp/guile$ git grep scm_open_byte_vector_input_port v2.0.11
> dak@lola:/usr/local/tmp/guile$ git grep scm_open_byte_vector_input_port origin/stable-2.0 
> dak@lola:/usr/local/tmp/guile$ 

You have mispelled the name of the function.  The following (untested)
code should work on Guile 2.0.5 or later:

   char *buf = c_str ();
   size_t len = strlen (buf);
   SCM bv = scm_c_make_bytevector (len);
   memcpy (SCM_BYTEVECTOR_CONTENTS (bv), buf, len);
   str_port_ = scm_open_bytevector_input_port (bv, SCM_UNDEFINED);

      Mark