Uri doesn't honour http-specialities

[defr0std]

• VSCode Version: 1.14.2
• OS Version: any

Steps to Reproduce:

1. Create and MD file and paste the following link:
   https://azure.microsoft.com/en-us/?ru=https%3A%2F%2Fmicrosoft.com%2F%3Fparam1%3Dvalue1%26param2%3Dvalue2

2. Preview and click on the link. You will be sent to https://azure.microsoft.com/en-us/?ru=https://microsoft.com/%3Fparam1=value1&param2=value2

Notice that the url parameter ru is an encoded link. VSCode decodes the parameter and the final link becomes incorrect. Just compare to how GitHub works when you click on the link in step 1.

Reproduces without extensions: Yes

[mjbvz]

I don't think this is markdown specific. I see the same behavior when clicking on that link in the editor. Root cause seems to be our Uri parsing logic:

URI.parse('https://azure.microsoft.com/en-us/?ru=https%3A%2F%2Fmicrosoft.com%2F%3Fparam1%3Dvalue1%26param2%3Dvalue2')

returns

https://azure.microsoft.com/en-us/?ru=https://microsoft.com/%3Fparam1=value1&param2=value2

Whereas

decodeURI('https://azure.microsoft.com/en-us/?ru=https%3A%2F%2Fmicrosoft.com%2F%3Fparam1%3Dvalue1%26param2%3Dvalue2')

returns

https://azure.microsoft.com/en-us/?ru=https%3A%2F%2Fmicrosoft.com%2F%3Fparam1%3Dvalue1%26param2%3Dvalue2

[jrieken]

Root cause seems to be our Uri parsing logic:

The parsing logic doesn't return a string as that comment suggests but simply parses an input string into URI components (scheme, auth, path, query, fragment). The toString-method does percent encoding everything (without looking at the scheme for more specialised encoding tricks). When called with false the toString-method does only encode & and ? because those are needed to parse it again.

Assuming that the result of toString can always be used in http or any other specialised protocol is not correct.

[jrieken]

dupe of #25852