len() string function in calc - basic/64k limit code pointers

[Michael Meeks]

Hi there,

On Wed, 2012-10-31 at 08:16 +0100, post wrote:
> I have a special request regarding spreadsheet functions.

	Ah - so, this list is really for reviewing patches, discussing quirks
of the code, and helping people develop fixes.

> When importing a string larger than 64k the len() function reports zero 
> length.

	Right - so there are tons of 64bit string limits around the code -
we're slowly removing them.

> Can the next version of Libreoffice handle strings larger than 64K in 
> calc? Or do the cell in calc have a string limit of 64k built in?

	The features of the next version are limited only by what people are
prepared to hack on :-) would you like some code pointers to get
involved in fixing this ? Encouragingly the ScStringCell has an
rtl::OUString embedded in it, so (quite possibly) there is just some
binding / truncation problem inside basic itself.

	If you see basic/source/runtime/methods.cxx and look for:

RTLFUNC(Len)
{
    (void)pBasic;
    (void)bWrite;

    if ( rPar.Count() != 2 )
        StarBASIC::Error( SbERR_BAD_ARGUMENT );
    else
    {
        const String& rStr = rPar.Get(1)->GetString();
        rPar.Get(0)->PutLong( (sal_Int32)rStr.Len() );
    }
}

	You can see that the problematic 'String' type is used (which truncates
to 64k lengths). I suspect you'd want to poke at:

	basic/inc/basic/sbxvar.hxx

	particularly the SbxValue and it's implementation inside:

	basic/source/sbx/sbxvalue.cxx

	To use rtl::OUString instead of String - that shouldn't be too hard,
it's easy to convert between the two for compatibility as you push the
perimiter of that wider.

	Patches most welcome,

	HTH !

		Michael.

-- 
michael.meeks at suse.com  <><, Pseudo Engineer, itinerant idiot