Re: [pdf-devel] Divison by zero in type 4 functions

[David Vazquez]

address@hidden writes:

> Hi all,
>
> If I understand correctly the following lines (1498 and 1511) from 
> pdf-fp-func.c
> aren't considering the case when "stack[sp] == 0".
> ##
>         case OPC_div:
>           if (sp < 1) goto stack_underflow;
>           stack[sp-1] /= stack[sp];
>           sp--;
>           break;
>
> [...]
>
>         case OPC_idiv:
>           if (sp < 1) goto stack_underflow;
>           if (!INT_P(stack[sp]) || !INT_P(stack[sp-1]))
>             goto type_error;
>           stack[sp-1] = INT(stack[sp]) / INT(stack[sp-1]);
>           sp--;
>           break;
> ###
>
>
> Is that a bug ?
>

Hi gerel,

It seems. I think there is similar errors (e.g: sqrt operand works on
real numbers and it does not check their parameter to be non-negative).

I am working on error management in type 4 functions. I think it would
be better finish this task first. Then, we can take a look to these
commands in the Postscript language reference, and check to it handles
errors correctly.