x/tools/gopls: panic on invalid filename

[kerma]

What version of Go are you using (go version)?

$ go version
go version go1.16.6 darwin/amd64

$ gopls version
golang.org/x/tools/gopls v0.7.3
    golang.org/x/tools/gopls@v0.7.3 h1:Lru57ht8vtDMouRskFC085VAjBAZRAISd/lwvwOOV0Q=

What did you do?

Used gopls via vim-go. Opened up one of the fugitive.vim plugin diff views, a textDocument/definition request was sent which crashed gopls.

What did you expect to see?

No panic, but ResponseMessage with ResponseError

What did you see instead?

The following request was sent to gopls:

Content-Length: 248
{"method": "textDocument/definition", "jsonrpc": "2.0", "id": 596, "params": {"textDocument": 
   {"uri": "fugitive%3A///Users/user/src/mm/ems/.git//0/pkg/domain/treasury/provider.go"}, 
   "position": {"character": 18, "line": 0}}}

This resulted in gopls panic:

panic: parse "fugitive%3A///Users/user/src/mm/ems/.git//0/pkg/domain/treasury/provider.go": 
invalid URI for request

---

I think that regressions was introduced in v0.7.1:
https://github.com/golang/tools/blob/e08545a2921d85f5ac0c3f1dde9997511237c957/internal/lsp/definition.go#L16

To be clear, I don't expect gopls to be able to handle things outside of defined URI scheme, but valid payload with invalid values should not result in panic.

[findleyr]

Thanks for the report, and investigation. You are correct about the root cause; fix incoming.

[gopherbot]

Change https://golang.org/cl/359734 mentions this issue: internal/lsp: check for invalid URIs in definition