3 files changed, 27 insertions, 12 deletions
diff --git a/runtime/lua/vim/lsp.lua b/runtime/lua/vim/lsp.lua
index f0845bfc80..4c453df3f6 100644
--- a/runtime/lua/vim/lsp.lua
+++ b/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
diff --git a/runtime/lua/vim/lsp/diagnostic.lua b/runtime/lua/vim/lsp/diagnostic.lua
index a1f24706c0..4e82c46fef 100644
--- a/runtime/lua/vim/lsp/diagnostic.lua
+++ b/runtime/lua/vim/lsp/diagnostic.lua
@@ -270,8 +270,10 @@ local function set_diagnostic_cache(diagnostics, bufnr, client_id)
       diagnostic.severity = DiagnosticSeverity.Error
     end
     -- Account for servers that place diagnostics on terminating newline
-    local start = diagnostic.range.start
-    start.line = math.min(start.line, buf_line_count - 1)
+    if buf_line_count > 0 then
+      local start = diagnostic.range.start
+      start.line = math.min(start.line, buf_line_count - 1)
+    end
   end
 
   diagnostic_cache[bufnr][client_id] = diagnostics
diff --git a/runtime/lua/vim/lsp/util.lua b/runtime/lua/vim/lsp/util.lua
index 6945d0f1ec..a75ab37508 100644
--- a/runtime/lua/vim/lsp/util.lua
+++ b/runtime/lua/vim/lsp/util.lua
@@ -518,13 +518,13 @@ end
 --- precedence is as follows: textEdit.newText > insertText > label
 --@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_completion
 local function get_completion_word(item)
-  if item.textEdit ~= nil and item.textEdit.newText ~= nil then
+  if item.textEdit ~= nil and item.textEdit.newText ~= nil and item.textEdit.newText ~= "" then
     if protocol.InsertTextFormat[item.insertTextFormat] == "PlainText" then
       return item.textEdit.newText
     else
       return M.parse_snippet(item.textEdit.newText)
     end
-  elseif item.insertText ~= nil then
+  elseif item.insertText ~= nil and item.insertText ~= "" then
     if protocol.InsertTextFormat[item.insertTextFormat] == "PlainText" then
       return item.insertText
     else
@@ -911,8 +911,8 @@ function M.preview_location(location)
   end
   local range = location.targetRange or location.range
   local contents = api.nvim_buf_get_lines(bufnr, range.start.line, range["end"].line+1, false)
-  local filetype = api.nvim_buf_get_option(bufnr, 'filetype')
-  return M.open_floating_preview(contents, filetype)
+  local syntax = api.nvim_buf_get_option(bufnr, 'syntax')
+  return M.open_floating_preview(contents, syntax)
 end
 
 --@private
@@ -1201,7 +1201,7 @@ end
 --- Shows contents in a floating window.
 ---
 --@param contents table of lines to show in window
---@param filetype string of filetype to set for opened buffer
+--@param syntax string of syntax to set for opened buffer
 --@param opts dictionary with optional fields
 --             - height    of floating window
 --             - width     of floating window
@@ -1214,10 +1214,10 @@ end
 --             - pad_bottom number of lines to pad contents at bottom
 --@returns bufnr,winnr buffer and window number of the newly created floating
 ---preview window
-function M.open_floating_preview(contents, filetype, opts)
+function M.open_floating_preview(contents, syntax, opts)
   validate {
     contents = { contents, 't' };
-    filetype = { filetype, 's', true };
+    syntax = { syntax, 's', true };
     opts = { opts, 't', true };
   }
   opts = opts or {}
@@ -1230,12 +1230,12 @@ function M.open_floating_preview(contents, filetype, opts)
   local width, height = M._make_floating_popup_size(contents, opts)
 
   local floating_bufnr = api.nvim_create_buf(false, true)
-  if filetype then
-    api.nvim_buf_set_option(floating_bufnr, 'filetype', filetype)
+  if syntax then
+    api.nvim_buf_set_option(floating_bufnr, 'syntax', syntax)
   end
   local float_option = M.make_floating_popup_options(width, height, opts)
   local floating_winnr = api.nvim_open_win(floating_bufnr, false, float_option)
-  if filetype == 'markdown' then
+  if syntax == 'markdown' then
     api.nvim_win_set_option(floating_winnr, 'conceallevel', 2)
   end
   api.nvim_buf_set_lines(floating_bufnr, 0, -1, true, contents)