Not sending hlint messages where there are no suggestions.

IHaskell/Eval/Evaluate.hs

@@ -161,7 +161,8 @@ evaluate kernelState code output = do
 
   when (getLintStatus kernelState /= LintOff) $ liftIO $ do
     lintSuggestions <- lint cmds
-    output True lintSuggestions
+    unless (null lintSuggestions) $
+      output True lintSuggestions
 
   updated <- runUntilFailure kernelState (map unloc cmds ++ [storeItCommand execCount])
   return updated {
@@ -670,4 +671,4 @@ formatGetType :: String -> String
 formatGetType = printf "<span style='font-weight: bold; color: green;'>%s</span>"
 
 displayError :: ErrMsg -> [DisplayData]
-displayError msg = [plain msg, html $ formatError msg] 
+displayError msg = [plain . typeCleaner $ msg, html $ formatError msg] 

IHaskell/Eval/Lint.hs

@@ -44,7 +44,11 @@ lint blocks = do
 
   writeFile (fromString filename) fileContents
   suggestions <- catMaybes <$> map parseSuggestion <$> hlint [filename, "--quiet"]
-  return [plain $ concatMap plainSuggestion suggestions, html $ htmlSuggestions suggestions]
+  return $
+    if null suggestions
+    then []
+    else
+      [plain $ concatMap plainSuggestion suggestions, html $ htmlSuggestions suggestions]
   where
     -- Join together multiple valid file blocks into a single file.
     -- However, join them with padding so that the line numbers are