SVG thumbnail doesn't render in "All properties"

Found in

EPiServer.CMS.UI 11.17.0

Fixed in

EPiServer.CMS.UI 11.20.1

Created

Mar 04, 2019

Updated

May 28, 2019

Area

CMS UI

State

Closed, Fixed and tested


Description

Steps to reproduce:
1. Add VectorImageFile.cs to Models > Media.

[ContentType(GUID = "F522B459-EB27-462C-B216-989FC7FF9448")]
[MediaDescriptor(ExtensionString = "svg")]
public class VectorImageFile : ImageData
{
    /// <summary>
    /// Gets the generated thumbnail for this media.
    /// </summary>
    public override Blob Thumbnail
    {
        get { return BinaryData; }
    }
}

2. Upload an svg file.
3. Add the svg file to the Alloy Plan page’s Teaser Image property (under the Content tab).

Expected
Should render thumbnail.

Actual
Thumbnail doesn't render.