Function with generic variable return type loses typing after first return

How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

Which OS are you using?

Linux

What is the issue affecting?

Type Checking

Expected Behaviour

ret2 in the example should be listed as string

Actual Behaviour

ret2 is listed as unknown

Reproduction steps

---@generic T
---@param arg T
---@return T ...
function GenericReturn(arg) end

local ret1, ret2 = GenericReturn("")

Additional Notes

Changing the return type to T|string correctly types the variable return but does not inherit the generic's typing.

Log File

No response

No source file or test is named. Begin by reproducing the generic return and vararg example in the issue, then trace the Lua language server's generic return-type inference and type-checking tests. Done means ret2 is inferred as string without changing the annotation, with a regression test covering the example.