Avoid potential multi-line progress lines

Without these changes, I get mutliple dots from QuickCheck on the terminal with

  --quickcheck-tests=1000000

Either of them suffices for a fix, but they both make sense.

core/Test/Tasty/Ingredients/ConsoleReporter.hs

@@ -142,7 +142,7 @@ buildTestOutput opts tree =
 
           | otherwise = do
               let
-                msg = case (progressText progress, 100 * progressPercent progress) of
+                msg = case (cleanupProgressText $ progressText progress, 100 * progressPercent progress) of
                         ("",  pct) -> printf "%.0f%%" pct
                         (txt, 0.0) -> printf "%s" txt
                         (txt, pct) -> printf "%s: %.0f%%" txt pct
@@ -196,6 +196,12 @@ buildTestOutput opts tree =
           }
           opts tree
 
+-- | Make sure the progress text does not contain any newlines or line feeds,
+-- lest our ANSI magic breaks. Since the progress text is expected to be short,
+-- we simply drop anything after a newline.
+cleanupProgressText :: String -> String
+cleanupProgressText = takeWhile $ \c -> c /= '\n' && c /= '\r'
+
 -- | Fold function for the 'TestOutput' tree into a 'Monoid'.
 --
 -- @since 0.12

quickcheck/Test/Tasty/QuickCheck.hs

@@ -232,8 +232,10 @@ quickCheck :: (Progress -> IO ())
            -> QC.Property
            -> IO QC.Result
 quickCheck yieldProgress args prop = do
+  -- Here we rely on the fact that QuickCheck currently prints its progress to
+  -- stderr and the overall status (which we don't need) to stdout
   tm <- QC.newTerminal
-          (\progressText -> yieldProgress emptyProgress { progressText })
+          (const $ pure ())
           (\progressText -> yieldProgress emptyProgress { progressText })
   QC.withState args $ \ s ->
     QC.test s { QC.terminal = tm } prop