Re: [PATCH 2/3] ios: Move file name normalization logic into ios-dev.h

[Egeyar Bagcioglu]

> I played with the stream IOS implementation using the following little
> Poke implementation of `strings' (yeah, it is the first Poke filter ever
> written, and as you can see it uses the strategy we foresaw at Mont
> Soleil):
>
> -----<-------
> #!/usr/local/bin/poke -L
> !#
>
> /* Printable ASCII characters: 0x20..0x7e */
>
> defvar stdin = open ("<stdin>");
> defvar stdout = open ("<stdout>");
>
> defvar offset = 0#B;
>
> try
> {
>    flush (stdin, offset);
>
>    defvar b = byte @ stdin : offset;
>    if (b >= 0x20 && b <= 0x7e)
>      byte @ stdout : iosize (stdout) = b;
>
>    offset = offset + 1#B;
> }
> until E_eof;
>
> close (stdin);
> close (stdout);
> ------>-------
>
> It works, up to some point:
>
> $ cat /usr/bin/ncal | ./pstrings
> poke: ../../libpoke/ios-buffer.h:244: ios_buffer_forget_till: Assertion 
> `buffer->end_offset >= buffer->begin_offset' failed.
> ELF> @m@8@@@@888WW ]] Aborted (core dumped)
>
> This is very exciting :)

Huh! This is a combination of a bug and the lack of error handling on my 
side.

1) Remember that IO spaces are bit-addressable while IO devices are byte 
addressable? This means that ios.c has to convert the offsets that it 
receives. Well, it turns out that I forgot that one for ios_flush. For 
each byte we process, the code was trying to forget 8 bytes.

2) Combine the above with the lack of error handling in stream ios and 
we get he bug you pointed out.

I am now sending the updated patch for stream ios and a patch to fix the 
error in (1).

Regards
Ege