Bug: Closing tags with spaces don't match

[alexolog]

Found in Cisual Studio Code, which uses this component.

Matching the following tags fails:

<tag>
</tag >

When the extra space is removed, the operation succeeds.

Note: Whitespace after the tag name is legal.
See https://stackoverflow.com/a/3314543/181238

Ref: microsoft/vscode#132873 (comment)