[hover] Display the last MarkedString when there are multiple.

[MaskRay]

    ;; We may receive multiple MarkedString's in the Hover response,
    ;; render the last one because others are likely comments which will
    ;; make the eldoc message span multiple lines.

For comments, @sebastiencs 's lsp-ui-doc.el should be preferred.

See emacs-lsp/lsp-ui#19 for some demos.

[vibhavp]

Why discard other lines? I think this could be better achieved by let-binding.

[MaskRay]

I discard other lines because only the last line is about function/variable/type signature, others are usually documentation. Displaying multiple lines in eldoc is less appealing. Too be more precise, we could filter out all languages other than ones with the language-id the server tells us.

rls

{"jsonrpc":"2.0","id":190,"result":{"contents":[" meow\n",{"language":"rust","value":"fn () -> i32"}],"range":null}}

cquery
"contents":[{"language":"text",...}, {"language":"cpp",...}]

The issue is that textDocument/hover does not encode the client "intention", whether it is displayed in a popup window (VSCode), or displayed in status bar / minibuffer (lsp-mode, LanguageClient-neovim#224). Without that, the language server has to return all necessary information but clients may have a problem rendering it.