AnyAttribute in AttributeGroup are ignored

[mariochr]

I am getting the following xsd (simplified) with different use of anyAttribute:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
 
 <!-- With attribute group it does not work -->
 <xs:complexType name="SaleType">
    <xs:attributeGroup ref="anyAttribute" />
 </xs:complexType> 
 
 <!-- Without attribute group it does work -->
 <xs:complexType name="OrderType">
    <xs:anyAttribute namespace="##other" />
 </xs:complexType> 
 
 <!-- If used with simple content it works-->
  <xs:complexType name="PurchaseType">
    <xs:simpleContent>
      <xs:extension base="xs:string">
        <xs:attributeGroup ref="anyAttribute" />
      </xs:extension>
    </xs:simpleContent>
  </xs:complexType>

<!-- Attribute group with anyAttribute -->
  <xs:attributeGroup name="anyAttribute">
    <xs:anyAttribute namespace="##other" />
  </xs:attributeGroup>

The problem is that only with the first one SaleType no code for anyAttribute is generated. Why is that?
As soon as I have an attributeGroup with anyAttribute in it no Code is generated for it, but If I add the anyAttribute in the complex type directly (OrderType) or if I have it in a simpleContent (complexContent does not work iirc) (PurchaseType) it works...

As a workaround I modify the xsd and put the anyAttribute in directly but there will be new versions in the future and I would rather avoid doing that.

Here the generated code (SaleType is completely empty except the interface which is also empty):

//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:4.0.30319.42000
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

// This code was generated by XmlSchemaClassGenerator version 2.1.1164.0
namespace Order
{
    
    
    [System.CodeDom.Compiler.GeneratedCodeAttribute("XmlSchemaClassGenerator", "2.1.1164.0")]
    [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute("SaleType", Namespace="")]
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    public partial class SaleType : IanyAttribute
    {
    }
    
    [System.CodeDom.Compiler.GeneratedCodeAttribute("XmlSchemaClassGenerator", "2.1.1164.0")]
    public partial interface IanyAttribute
    {
    }
    
    [System.CodeDom.Compiler.GeneratedCodeAttribute("XmlSchemaClassGenerator", "2.1.1164.0")]
    [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute("OrderType", Namespace="")]
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    public partial class OrderType
    {
        
        [System.Xml.Serialization.XmlIgnoreAttribute()]
        private System.Collections.Generic.List<System.Xml.XmlAttribute> _anyAttribute;
        
        [System.Xml.Serialization.XmlAnyAttributeAttribute()]
        public System.Collections.Generic.List<System.Xml.XmlAttribute> AnyAttribute
        {
            get
            {
                return _anyAttribute;
            }
            private set
            {
                _anyAttribute = value;
            }
        }
        
        /// <summary>
        /// <para xml:lang="en">Gets a value indicating whether the AnyAttribute collection is empty.</para>
        /// </summary>
        [System.Xml.Serialization.XmlIgnoreAttribute()]
        public bool AnyAttributeSpecified
        {
            get
            {
                return (this.AnyAttribute.Count != 0);
            }
        }
        
        /// <summary>
        /// <para xml:lang="en">Initializes a new instance of the <see cref="OrderType" /> class.</para>
        /// </summary>
        public OrderType()
        {
            this._anyAttribute = new System.Collections.Generic.List<System.Xml.XmlAttribute>();
        }
    }
    
    [System.CodeDom.Compiler.GeneratedCodeAttribute("XmlSchemaClassGenerator", "2.1.1164.0")]
    [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute("PurchaseType", Namespace="")]
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    public partial class PurchaseType : IanyAttribute
    {
        
        /// <summary>
        /// <para xml:lang="en">Gets or sets the text value.</para>
        /// </summary>
        [System.Xml.Serialization.XmlTextAttribute()]
        public string Value { get; set; }
        
        [System.Xml.Serialization.XmlIgnoreAttribute()]
        private System.Collections.Generic.List<System.Xml.XmlAttribute> _anyAttribute;
        
        [System.Xml.Serialization.XmlAnyAttributeAttribute()]
        public System.Collections.Generic.List<System.Xml.XmlAttribute> AnyAttribute
        {
            get
            {
                return _anyAttribute;
            }
            private set
            {
                _anyAttribute = value;
            }
        }
        
        /// <summary>
        /// <para xml:lang="en">Gets a value indicating whether the AnyAttribute collection is empty.</para>
        /// </summary>
        [System.Xml.Serialization.XmlIgnoreAttribute()]
        public bool AnyAttributeSpecified
        {
            get
            {
                return (this.AnyAttribute.Count != 0);
            }
        }
        
        /// <summary>
        /// <para xml:lang="en">Initializes a new instance of the <see cref="PurchaseType" /> class.</para>
        /// </summary>
        public PurchaseType()
        {
            this._anyAttribute = new System.Collections.Generic.List<System.Xml.XmlAttribute>();
        }
    }
}

Edit:

I found another weird case with complexContent:

  <xs:complexType name="StockTypeBase" />
  
  <xs:complexType name="StockType1">
    <xs:complexContent>
      <xs:extension base="StockTypeBase">	  
	 <xs:anyAttribute namespace="##other" />
      </xs:extension>
    </xs:complexContent>
  </xs:complexType>
  
  <xs:complexType name="StockType2">
    <xs:complexContent>
      <xs:extension base="StockTypeBase">
        <xs:attributeGroup ref="anyAttribute" />
      </xs:extension>
    </xs:complexContent>
  </xs:complexType>

StockType1has the anyAttribute while StockType2 has it with the attributeGroup.

But in the produced code all types are empty:

    [System.CodeDom.Compiler.GeneratedCodeAttribute("XmlSchemaClassGenerator", "2.1.1164.0")]
    [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute("StockTypeBase", Namespace="")]
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    [System.Xml.Serialization.XmlIncludeAttribute(typeof(StockType1))]
    [System.Xml.Serialization.XmlIncludeAttribute(typeof(StockType2))]
    public partial class StockTypeBase
    {
    }
    
    [System.CodeDom.Compiler.GeneratedCodeAttribute("XmlSchemaClassGenerator", "2.1.1164.0")]
    [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute("StockType1", Namespace="")]
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    public partial class StockType1 : StockTypeBase
    {
    }
    
    [System.CodeDom.Compiler.GeneratedCodeAttribute("XmlSchemaClassGenerator", "2.1.1164.0")]
    [System.SerializableAttribute()]
    [System.Xml.Serialization.XmlTypeAttribute("StockType2", Namespace="")]
    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.ComponentModel.DesignerCategoryAttribute("code")]
    public partial class StockType2 : StockTypeBase, IanyAttribute
    {
    }