[fpc-pascal] Code works on Linux x64 but not on Linux x86

[Sven Barth]

On 07.02.2012 17:12, Reinier Olislagers wrote:
> I have the following code, adapted from pasbzip.pas (bzip2 example)
> uses ...bzip2..
>
> const
>    BufferSize = 4096;
> var
>    infile, outfile: Tbufstream;
>    decoder: Tbzip2_decode_stream;
>    a: array[1..BufferSize] of byte;
>    readsize: cardinal;
>    Status: boolean;
> begin
>    Status := False;
>    result:=false;
> ...
>    try
>      infile.init(SourceFile, stopenread, 4096);
>      outfile.init(TargetFile, stcreate, 4096);
>      decoder.init(@infile);
>      if decoder.status<>  stok then
>      begin
> ...
>        repeat
>          readsize := BufferSize;
>          decoder.Read(a, readsize);
>          Dec(readsize, decoder.short);
>          outfile.Write(a, readsize);
>        until decoder.status<>  0;
>      end;
>      infile.done;
>      outfile.done;
> ...
>
> Code bombs at decoder.Read(a, readsize). readsize=0 according to debugger.
> readsize=cardinal; according to help "an unsigned 32-bit integer".
> However,
> http://wiki.lazarus.freepascal.org/Multiplatform_Programming_Guide#32.2F64_bit
> seems to imply Cardinal can vary between 32 bit and 64 bit.
>
> Is that the culprit or am I doing anyth else wrong?

Does your stream contain at least 4096 bytes? According to the 
documentation here 
http://www.freepascal.org/docs-html/rtl/objects/tstream.read.html the 
Read procedure does not perform any check.
Important note in case you're not aware of it: Tbzip2_decode_stream is 
NOT a descendant of Classes.TStream, but of Objects.TStream, thus you 
should look at the documentation of unit Objects (you can reach it from 
the above mentioned link).

Also "Cardinal" is always 32-Bit wide. The only types that change 
depending on bitness are "Pointer", "PtrUInt" and "PtrInt".

Regards,
Sven