lsp: Force re-display of diagnostics when opening a file

runtime/lua/vim/lsp.lua

@@ -293,6 +293,19 @@ local function text_document_did_open_handler(bufnr, client)
   }
   client.notify('textDocument/didOpen', params)
   util.buf_versions[bufnr] = params.textDocument.version
+
+  -- Next chance we get, we should re-do the diagnostics
+  vim.schedule(function()
+    vim.lsp.handlers["textDocument/publishDiagnostics"](
+      nil,
+      "textDocument/publishDiagnostics",
+      {
+        diagnostics = vim.lsp.diagnostic.get(bufnr, client.id),
+        uri = vim.uri_from_bufnr(bufnr),
+      },
+      client.id
+    )
+  end)
 end
 
 -- FIXME: DOC: Shouldn't need to use a dummy function