randomly got System.NotSupportedException: 'TypeConverter' is unable to convert 'HandlebarsDotNet.UndefinedBindingResult' to 'xxx'

[yindf]

Describe the bug

got exception when use with block inside each

Expected behavior:

no exception

Test to reproduce

{{#each Fields}}
{{#with this as | field |}}                     <------------------ blockParamsValues[0] = arguments[0]; will fail here during the loop.
{{#each (Getattributes field)}}                 <------------------ then 'field' here will got exception.
    {{this}}
{{/each}}
{{/with}}
{{/each}}

Other related info

I got the exception from debugger and find that the bug is caused by :
internal struct BindingContextPolicy : IInternalObjectPoolPolicy
{
public BindingContext Create() => new BindingContext();

public bool Return(BindingContext item)
{
    item.Root = null;
    item.Value = null;
    item.ParentContext = null;
    item.PartialBlockTemplate = null;
    item.InlinePartialTemplates.Clear();
    item.Helpers.Clear();
    item.BlockHelpers.Clear();
    item.Bag.Clear();

    item.BlockParamsObject.OptionalClear(); //  <------------ bug caused by this
    item.ContextDataObject.OptionalClear();
    
    item.Descriptor.Reset();

    return true;
}

}

in the with WithBlockHelperDescriptor :

        using var frame = options.CreateFrame(arguments[0]);
        var blockParamsValues = frame.BlockParams(options.BlockVariables);
        blockParamsValues[0] = arguments[0];  // <---------------- when BindingContext got from pool and frame.BlockParamsObject has the key already, but has count == 0 ( Reset by OptionalClear ),  in FixedSizeDictionary.AddOrReplace(variable, value, out _); the key, value will be set correctly, but the count is still 0.

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After submitting the issue