[xml] XML Schema: Nillable custom type error (PATCH)

[Sir Woody Hackswell <woody hackswell com>]

Hello, all!  I believe I've come across a problem with Schema validation.

Here's my scenario:
I have a custom type (in this example, "pricetype".  My Element is 
nillable, but the validator always bombs on it, because the "" item 
isn't in my xs:pattern list.  Nillable should hit before we check 
patterns, no?  Below my example is a small patch.  Thank you.

-Richard Balint
woody @AT@ hackswell.DOT.com

XML:
<?xml version="1.0" encoding="UTF-8"?>

<Book>
   <Title>How to Write XML</Title>
   <Author>Richard Balint</Author>
   <Price></Price>
</Book>


XSD:
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema";>

 <xs:element name="Book">
   <xs:complexType>
     <xs:sequence>
       <xs:element name="Title" type="xs:string"/>
       <xs:element name="Author" type="xs:string"/>
       <xs:element name="Price" type="pricetype" nillable="1" />
     </xs:sequence>
   </xs:complexType>
 </xs:element>

 <xs:simpleType name="pricetype">
   <xs:restriction base="xs:string">
     <xs:pattern value="$\d+\.\d\d"/>
   </xs:restriction>
 </xs:simpleType>

</xs:schema>



Patch against libxml2-2.6.22:

--- xmlschemas.c.orig   2005-09-12 17:39:46.000000000 -0400
+++ xmlschemas.c        2005-11-05 20:16:04.000000000 -0500
@@ -21494,6 +21494,10 @@
               ret = xmlRegexpExec(facetLink->facet->regexp, value);
               if (ret == 1)
                   break;
+        else if ((type->flags & XML_SCHEMAS_ELEM_NILLABLE) && (*value 
== '\0')) {
+            ret = 1;
+            break;
+        }
               else if (ret < 0) {
                   AERROR_INT("xmlSchemaValidateFacets",
                       "validating against a pattern facet");
@@ -23100,11 +23104,16 @@
       return (xmlSchemaVCheckCVCSimpleType(
           ACTXT_CAST vctxt, NULL,
           type, value, &(inode->val), 1, 1, 0));
-    else
+    else {
+
+      if (inode->decl->flags & XML_SCHEMAS_ELEM_NILLABLE) {
+        type->flags |= XML_SCHEMAS_ELEM_NILLABLE;
+      }
       return (xmlSchemaVCheckCVCSimpleType(
           ACTXT_CAST vctxt, NULL,
           type, value, NULL, 1, 0, 0));
}
+}