Patched WebViewPage base class

PatchedWebViewPage.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.WebPages;
using System.Web.WebPages.Instrumentation;

namespace MvcApplication1.Patches
{
    public abstract class PatchedWebViewPage : WebViewPage
    {
        protected override void WriteAttributeTo(string pageVirtualPath, TextWriter writer, string name, PositionTagged<string> prefix, PositionTagged<string> suffix, params AttributeValue[] values)
        {
            bool first = true;
            bool wroteSomething = false;
            if (values.Length == 0)
            {
                // Explicitly empty attribute, so write the prefix and suffix
                WritePositionTaggedLiteral(writer, pageVirtualPath, prefix);
                WritePositionTaggedLiteral(writer, pageVirtualPath, suffix);
            }
            else
            {
                for (int i = 0; i < values.Length; i++)
                {
                    AttributeValue attrVal = values[i];
                    PositionTagged<object> val = attrVal.Value;
                    PositionTagged<string> next = i == values.Length - 1 ?
                        suffix : // End of the list, grab the suffix
                        values[i + 1].Prefix; // Still in the list, grab the next prefix

                    bool? boolVal = null;
                    if (val.Value is bool)
                    {
                        boolVal = (bool)val.Value;
                    }

                    if (val.Value != null && (boolVal == null || boolVal.Value))
                    {
                        string valStr = val.Value as string;
                        // This shouldn't be needed any more
                        //if (valStr == null)
                        //{
                        //    valStr = val.Value.ToString();
                        //}
                        if (boolVal != null)
                        {
                            valStr = name;
                        }

                        if (first)
                        {
                            WritePositionTaggedLiteral(writer, pageVirtualPath, prefix);
                            first = false;
                        }
                        else
                        {
                            WritePositionTaggedLiteral(writer, pageVirtualPath, attrVal.Prefix);
                        }

                        // Calculate length of the source span by the position of the next value (or suffix)
                        int sourceLength = next.Position - attrVal.Value.Position;

                        BeginContext(writer, pageVirtualPath, attrVal.Value.Position, sourceLength, isLiteral: attrVal.Literal);
                        if (attrVal.Literal)
                        {
                            WriteLiteralTo(writer, val.Value);
                        }
                        else
                        {
                            // Patch: Don't use valStr, use val.Value
                            WriteTo(writer, val.Value); // Write value
                        }
                        EndContext(writer, pageVirtualPath, attrVal.Value.Position, sourceLength, isLiteral: attrVal.Literal);
                        wroteSomething = true;
                    }
                }
                if (wroteSomething)
                {
                    WritePositionTaggedLiteral(writer, pageVirtualPath, suffix);
                }
            }
        }

        private void WritePositionTaggedLiteral(TextWriter writer, string pageVirtualPath, string value, int position)
        {
            BeginContext(writer, pageVirtualPath, position, value.Length, isLiteral: true);
            WriteLiteralTo(writer, value);
            EndContext(writer, pageVirtualPath, position, value.Length, isLiteral: true);
        }

        private void WritePositionTaggedLiteral(TextWriter writer, string pageVirtualPath, PositionTagged<string> value)
        {
            WritePositionTaggedLiteral(writer, pageVirtualPath, value.Value, value.Position);
        }
    }
}

PatchedWebViewPageOfT.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.WebPages;
using System.Web.WebPages.Instrumentation;

namespace MvcApplication1.Patches
{
    public abstract class PatchedWebViewPage<T> : WebViewPage<T>
    {
        protected override void WriteAttributeTo(string pageVirtualPath, TextWriter writer, string name, PositionTagged<string> prefix, PositionTagged<string> suffix, params AttributeValue[] values)
        {
            bool first = true;
            bool wroteSomething = false;
            if (values.Length == 0)
            {
                // Explicitly empty attribute, so write the prefix and suffix
                WritePositionTaggedLiteral(writer, pageVirtualPath, prefix);
                WritePositionTaggedLiteral(writer, pageVirtualPath, suffix);
            }
            else
            {
                for (int i = 0; i < values.Length; i++)
                {
                    AttributeValue attrVal = values[i];
                    PositionTagged<object> val = attrVal.Value;
                    PositionTagged<string> next = i == values.Length - 1 ?
                        suffix : // End of the list, grab the suffix
                        values[i + 1].Prefix; // Still in the list, grab the next prefix

                    bool? boolVal = null;
                    if (val.Value is bool)
                    {
                        boolVal = (bool)val.Value;
                    }

                    if (val.Value != null && (boolVal == null || boolVal.Value))
                    {
                        string valStr = val.Value as string;
                        // This shouldn't be needed any more
                        //if (valStr == null)
                        //{
                        //    valStr = val.Value.ToString();
                        //}
                        if (boolVal != null)
                        {
                            valStr = name;
                        }

                        if (first)
                        {
                            WritePositionTaggedLiteral(writer, pageVirtualPath, prefix);
                            first = false;
                        }
                        else
                        {
                            WritePositionTaggedLiteral(writer, pageVirtualPath, attrVal.Prefix);
                        }

                        // Calculate length of the source span by the position of the next value (or suffix)
                        int sourceLength = next.Position - attrVal.Value.Position;

                        BeginContext(writer, pageVirtualPath, attrVal.Value.Position, sourceLength, isLiteral: attrVal.Literal);
                        if (attrVal.Literal)
                        {
                            WriteLiteralTo(writer, val.Value);
                        }
                        else
                        {
                            // Patch: Don't use valStr, use val.Value
                            WriteTo(writer, val.Value); // Write value
                        }
                        EndContext(writer, pageVirtualPath, attrVal.Value.Position, sourceLength, isLiteral: attrVal.Literal);
                        wroteSomething = true;
                    }
                }
                if (wroteSomething)
                {
                    WritePositionTaggedLiteral(writer, pageVirtualPath, suffix);
                }
            }
        }

        private void WritePositionTaggedLiteral(TextWriter writer, string pageVirtualPath, string value, int position)
        {
            BeginContext(writer, pageVirtualPath, position, value.Length, isLiteral: true);
            WriteLiteralTo(writer, value);
            EndContext(writer, pageVirtualPath, position, value.Length, isLiteral: true);
        }

        private void WritePositionTaggedLiteral(TextWriter writer, string pageVirtualPath, PositionTagged<string> value)
        {
            WritePositionTaggedLiteral(writer, pageVirtualPath, value.Value, value.Position);
        }
    }
}

Views\\web.config

<!-- All need to change is the pageBaseType on the <pages> element. Change it to point at your patched page base class. MVC will automatically pick the generic version if @model is used. -->
<configuration>
  <system.web.webPages.razor>
    <pages pageBaseType="MvcApplication1.Patches.PatchedWebViewPage">
    </pages>
  </system.web.webPages.razor>
</configuration>

Viewsweb.config

<!-- All need to change is the pageBaseType on the <pages> element. Change it to point at your patched page base class. MVC will automatically pick the generic version if @model is used. -->
<configuration>
  <system.web.webPages.razor>
    <pages pageBaseType="MvcApplication1.Patches.PatchedWebViewPage">
    </pages>
  </system.web.webPages.razor>
</configuration>