localhost autolinks

[joriszwart]

It looks like auto linking doesn't work for localhost (and other single part domains):

http://localhost:5000 # not rendered
http://localhost.dev:5000 # rendered
http://example:5000 # not rendered

This may be intentional, but I have not found anything like this in the autolink extension.

[dmitry-azaraev]

This looks like method IsValidDomain requires to have at least two segments (i did not know if it is exist other assumptions about in other places).

markdig/src/Markdig/Extensions/AutoLinks/AutoLinkParser.cs

Line 167 in 49cf59b

if (c != 't' && !LinkHelper.IsValidDomain(link, domainOffset))

[snnz]

GFM spec says:

An extended www autolink will be recognized when the text www. is found followed by a valid domain. A valid domain consists of segments of alphanumeric characters, underscores (_) and hyphens (-) separated by periods (.). There must be at least one period ...

and then:

An extended url autolink will be recognised when one of the schemes http://, or https://, followed by a valid domain

One would think that "There must be at least one period" is related to the definition of the valid domain, but it seems to apply to the www autolinks only.