Re: Gtk::TreeStore insert_with_values weirdness

[muppet <scott asofyet org>]

On Jan 4, 2007, at 10:53 AM, Jens Luedicke wrote:

> On 1/3/07, Roderich Schupp <roderich schupp googlemail com> wrote:
>
> > Are you using the XS variant of Readonly (i.e. have Readonly::XS  
> > installed)
> > or the pure-perl variant? The latter implements readonly scalars  
> > as tied scalars
> > (with a STORE method that just croaks)... My guess is that the XS  
> > glue in
> > Gtk::TreeStore (at least) doesn't cope with tied scalars (you need  
> > extra
> > code to handle tied scalars from XS).
>
> Same problem with Readonly::XS.
> Another thing I noticed: Only $COL_FILEINFO (== 0) is affected. I can
> use the other two Readonly scalars just fine.

Perhaps the get magic is returning undef or empty string when the  
value is zero?

Does it work fine when you don't use Readonly here?

The code in insert_with_values() attempts to do some extra sanity  
checking on the input to give meaningful and helpful error messages  
to the hapless programmer who may be guessing at the API.  The logic is

     for each column/value pair on the stack
         get the column id scalar
         if the column id scalar doesn't look like a number
             croak
         get the column id by coercing the scalar to an integer
         put the value scalar into a GValue

We did that because if you don't, then any failed conversion of a non- 
number to a number give you zero --- silently using column 0 for  
everything that you wrote incorrectly.  Mystifying -> Frustrating ->  
Infuriating.


Now, perl's looks_like_number() function is implemented like this:

       if the "i'm a string" flag is on
           get the string with SvPVX()
       else if i can be coerced into a string
           get the string with SvPV()
       else
           return true if any of the "number ok" or "integer ok"  
flags are on
       return the result of the function that parses a number

It would be interesting to know which of those tests is failing  
here.   Are we failing on bad handling of get magic?  Does the  
Readonly variable refuse to be coerced into a string?