Wingman: case split on variable deletes existing function definition

[jhrcek]

Your environment

haskell-language-server version: 1.0.0.0 (GHC: 8.8.4) (PATH: /home/jhrcek/.local/bin/haskell-language-server-wrapper) (GIT hash: 94573be3144fa47da0ebe547b62f0e172f48c40d)
Tool versions found on the $PATH
cabal:		3.4.0.0
stack:		2.5.1
ghc:		8.10.4

Which lsp-client do you use: vscode

Steps to reproduce

data A = A | B | C

some :: A -> IO ()
some a = do
    foo
    bar a
  where
      foo = putStrLn "Hi"
      
      bar :: A -> IO ()
      bar x = _ -- hover over this hole and pick "Case split on x"

Expected behaviour

Case split should only affect the helper function bar and should not delete existing code.

Actual behaviour

[isovector]

Great timing! I was just looking for a test case for this.