Re: [xml] "double"s and schema validation

[Csaba Raduly <rcsaba gmail com>]

On Wed, Jul 21, 2010 at 6:19 PM, Andrew W. Nosenko  wrote:
> On Wed, Jul 21, 2010 at 14:23, Csaba Raduly wrote:
> > On Tue, Jul 20, 2010 at 3:40 AM, Dan Sommers  wrote:
...
> > > I tracked it down to xmlschematypes.c, starting around line 2465, where
> > > it starts scanning the input for something suitable for sscanf("%lf").
> > > Should that code contain an extra check that there is at least one digit
> > > somewhere?
> >
> > I think you are right. This code:
> >                while ((*cur >= '0') && (*cur <= '9')) {
> >                    cur++;
> >                }
> > accepts 0 or more digits (before the period); perhaps it should check
> > for 1 or more digits instead:
>
> No!  The case like ".5" instead of "0.5" is perfectly valid and widely used!
> Whether the "." or "e" are valid string representation of the "double"
> type or should be rejected -- it's another matter.  But zero digits
> before dot are absolutely correct and should be allowed.

Just because it's widely used it doesn't mean that it is "absolutely correct" :)
(Also, the rules for what's a valid float in C may not be the same for XSD)

Anyway, here's a revised version:
--- xmlschemastypes2.c  2010-07-21 13:17:12.229467800 +0200
+++ xmlschemastypes.c   2010-07-22 14:00:05.965759600 +0200
@@ -2392,6 +2392,8 @@
         case XML_SCHEMAS_DOUBLE:{
                 const xmlChar *cur = value;
                 int neg = 0;
+                int digits_before = 0;
+                int digits_after  = 0;

         if (normOnTheFly)
             while IS_WSP_BLANK_CH(*cur) cur++;
@@ -2463,13 +2465,16 @@
                 if ((cur[0] == 0) || (cur[0] == '+') || (cur[0] == '-'))
                     goto return1;
                 while ((*cur >= '0') && (*cur <= '9')) {
-                    cur++;
+                    digits_before++; cur++;
                 }
                 if (*cur == '.') {
                     cur++;
-                    while ((*cur >= '0') && (*cur <= '9'))
-                        cur++;
+                    while ((*cur >= '0') && (*cur <= '9')) {
+                        digits_after++; cur++;
+                    }
                 }
+                if (digits_before + digits_after == 0)
+                    goto return1;
                 if ((*cur == 'e') || (*cur == 'E')) {
                     cur++;
                     if ((*cur == '-') || (*cur == '+'))



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