Fixed runtime error with compactify'DL on certain lists.

Closes #1452.  Added test.

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/Tests/Shared.hs b/tests/Tests/Shared.hs
index 8c7c31674..c9e2e21f5 100644
--- a/tests/Tests/Shared.hs
+++ b/tests/Tests/Shared.hs
@@ -5,6 +5,10 @@ import Text.Pandoc.Shared
 import Test.Framework
 import Tests.Helpers
 import Tests.Arbitrary()
+import Test.Framework.Providers.HUnit
+import Test.HUnit ( assertBool )
+import Text.Pandoc.Builder
+import Data.Monoid
 
 tests :: [Test]
 tests = [ testGroup "normalize"
@@ -13,6 +17,12 @@ tests = [ testGroup "normalize"
           , property "p_normalize_no_trailing_spaces"
               p_normalize_no_trailing_spaces
           ]
+        , testGroup "compactify'DL"
+          [ testCase "compactify'DL with empty def" $
+              assertBool "compactify'DL"
+              (let x = [(str "word", [para (str "def"), mempty])]
+               in  compactify'DL x == x)
+          ]
         ]
 
 p_normalize_blocks_rt :: [Block] -> Bool