bug with read-string!/partial

bug with read-string!/partial

[Han-Wen Nienhuys]

Hi,

what's the proper way to use read-string!/partial ?

If I read a file with fewer bytes than the arg of read-string!/partial,
I get problems down the line, when

   char *
   scm_to_locale_stringn (SCM str, size_t *lenp)

checks whether

  memcpy (res, scm_i_string_chars (str), len);
   if (lenp == NULL)
     {
       res[len] = '\0';
       if (strlen (res) != len)
	{
	  free (res);
	  scm_misc_error (NULL,
			  "string contains #\\nul character: ~S",
			  scm_list_1 (str));
	}
     }

In addition, I this error message isn't printed properly, but I get

   Converting to PNG...throw from within critical section.
   Geannuleerd
   muurbloem:~/src/lilypond$


-- 
  Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen


_______________________________________________
Guile-devel mailing list
Guile-devel@gnu.org
http://lists.gnu.org/mailman/listinfo/guile-devel

Re: bug with read-string!/partial

[Han-Wen Nienhuys]

Han-Wen Nienhuys wrote:
> 
> Hi,
> 
> what's the proper way to use read-string!/partial ?
> 
> If I read a file with fewer bytes than the arg of read-string!/partial,
> I get problems down the line, when
> 
>   char *
>   scm_to_locale_stringn (SCM str, size_t *lenp)
> 
> checks whether
> 
>  memcpy (res, scm_i_string_chars (str), len);
>   if (lenp == NULL)
>     {
>       res[len] = '\0';
>       if (strlen (res) != len)
>     {
>       free (res);
>       scm_misc_error (NULL,
>               "string contains #\\nul character: ~S",
>               scm_list_1 (str));
>     }
>     }
> 
> In addition, I this error message isn't printed properly, but I get
> 
>   Converting to PNG...throw from within critical section.
>   Geannuleerd
>   muurbloem:~/src/lilypond$
> 
> 

additional information: this comes from regex-posix.c

   c_str = scm_to_locale_string (substr);
   status = regexec (SCM_RGX (rx), c_str, nmatches, matches,
		    scm_to_int (flags));
   free (c_str);

why is this using null-delimited strings?


-- 
  Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen


_______________________________________________
Guile-devel mailing list
Guile-devel@gnu.org
http://lists.gnu.org/mailman/listinfo/guile-devel

Re: bug with read-string!/partial

[Kevin Ryde]

Han-Wen Nienhuys <hanwen@xs4all.nl> writes:
>
> why is this using null-delimited strings?

I think that's all posix provides.  Separate regexp libraries might do
better.  I was going to add a note about no nulls in the manual, but
never did.


Speaking of regexps, what I think I will do for the docs is put
someting like the following about locale chars.  (I got into trouble
trying to match some shift-jis bytes when in a utf-8 locale.)


   POSIX regexp functions interpret both regexps and input strings in
the locale character set.  Since Guile strings are currently merely
bytes (*note Conversion to/from C::), care should be taken when working
with non-ASCII characters.  If `setlocale' has been called and selects
a multibyte codeset (*note Locales::), then non-ASCII bytes may be
interpreted as a multibyte character.


_______________________________________________
Guile-devel mailing list
Guile-devel@gnu.org
http://lists.gnu.org/mailman/listinfo/guile-devel

Re: bug with read-string!/partial

[Kevin Ryde]

Han-Wen Nienhuys <hanwen@xs4all.nl> writes:
>
> what's the proper way to use read-string!/partial ?
>
> If I read a file with fewer bytes than the arg of read-string!/partial,
> I get problems down the line,

It leaves the rest of the string with whatever was there before, I
think you normally have to do substring or substring/shared to get the
good portion.


_______________________________________________
Guile-devel mailing list
Guile-devel@gnu.org
http://lists.gnu.org/mailman/listinfo/guile-devel

Re: bug with read-string!/partial

[Marius Vollmer]

Han-Wen Nienhuys <hanwen@xs4all.nl> writes:

> Hi,
>
> what's the proper way to use read-string!/partial ?
>
> If I read a file with fewer bytes than the arg of read-string!/partial,
> I get problems down the line [with scm_to_locale_stringn]

Do you pass the right length to scm_to_locale_stringn, i.e, the return
value of read-string!/partial?

Also, maybe there really are #\nul characters in the file and the
error message from scm_to_locale_stringn is entirely deserved.

> In addition, I this error message isn't printed properly, but I get
>
>    Converting to PNG...throw from within critical section.
>    Geannuleerd
>    muurbloem:~/src/lilypond$

This message means that SCM_CRITICAL_SECTION_START/END is used
improperly.  There are likely some improper uses in Guile itself (and
this issue is what is holding off the 1.8 release at the moment...),
so it would be good to know exactly what instance of
SCM_CRITICAL_SECTION_START/END is responsible for your abort.

-- 
GPG: D5D4E405 - 2F9B BCCC 8527 692A 04E3  331E FAF8 226A D5D4 E405


_______________________________________________
Guile-devel mailing list
Guile-devel@gnu.org
http://lists.gnu.org/mailman/listinfo/guile-devel