Named xs:simpleType based on xs:string incorrectly generates List<string> instead of string

[SMAmch]

Problem description

Given this XSD:

<xs:simpleType name="BitmapWeek">
    <xs:restriction base="xs:string">
        <xs:minLength value="7"/>
        <xs:maxLength value="7"/>
        <xs:pattern value="[0-1]{7}"/>
    </xs:restriction>
</xs:simpleType>

The generator produces:

[XmlIgnore]
private List<string> _weeklyPattern;

[XmlElement("WeeklyPattern", Order = 3)]
public List<string> WeeklyPattern
{
    get => _weeklyPattern;
    set => _weeklyPattern = value;
}

[XmlIgnore]
public bool WeeklyPatternSpecified =>
    WeeklyPattern != null && WeeklyPattern.Count != 0;

This is incorrect.
BitmapWeek is a simple string type, not a list.

Expected output

The generator should produce:

[MinLength(7)]
[MaxLength(7)]
[RegularExpression("[0-1]{7}")]
[XmlElement("WeeklyPattern", Order = 3)]
public string WeeklyPattern { get; set; }

Why this is a bug

The generator behaves correctly when the simpleType is inline inside an element, e.g.:

<xs:element name="BitmapDays">
    <xs:simpleType>
        <xs:restriction base="xs:string">
            <xs:minLength value="1"/>
            <xs:maxLength value="740"/>
            <xs:pattern value="[0-1]{1,740}"/>
        </xs:restriction>
    </xs:simpleType>
</xs:element>

This produces the correct C#:

[MinLength(1)]
[MaxLength(740)]
[RegularExpression("[0-1]{1,740}")]
[XmlElement("BitmapDays", Order = 0)]
public string BitmapDays { get; set; }

Seems like there is a problem with named simple types.

Would be nice if there is a fix for that. Currently I manually change the generated file because I can't change the xsd.

[mganss]

Where's the WeeklyPattern in the xsd in the first example?

[SMAmch]

Ah sorry I really missed that those are 2 different types.

<xs:element name="WeeklyPattern" type="BitmapWeek">
	<xs:annotation>
		<xs:documentation>The first day is monday.</xs:documentation>
	</xs:annotation>
</xs:element>

The problem should still be the same or similar though.