diff --git a/src/app/MetaBrush/Action.hs b/src/app/MetaBrush/Action.hs
index 3b4904d..d783709 100644
--- a/src/app/MetaBrush/Action.hs
+++ b/src/app/MetaBrush/Action.hs
@@ -383,6 +383,17 @@ data Redo = Redo
 instance HandleAction Redo where
   handleAction _ _ _ = pure ()
 
+---------------------
+-- Discard changes --
+---------------------
+
+data DiscardChanges = DiscardChanges
+  deriving stock Show
+
+-- TODO
+instance HandleAction DiscardChanges where
+  handleAction _ _ _ = pure ()
+
 ---------
 -- Cut --
 ---------
diff --git a/src/app/MetaBrush/UI/Menu.hs b/src/app/MetaBrush/UI/Menu.hs
index 76f3134..96cd2bd 100644
--- a/src/app/MetaBrush/UI/Menu.hs
+++ b/src/app/MetaBrush/UI/Menu.hs
@@ -134,16 +134,17 @@ data FileMenu ( rt :: ResourceType )
 
 data EditMenu ( rt :: ResourceType )
   = EditMenu
-  { undo        :: !( MenuItem Undo      NoSubresource rt )
-  , redo        :: !( MenuItem Redo      NoSubresource rt )
-  , editSep1    :: !( Separator rt )
-  , cut         :: !( MenuItem Cut       NoSubresource rt )
-  , copy        :: !( MenuItem Copy      NoSubresource rt )
-  , paste       :: !( MenuItem Paste     NoSubresource rt )
-  , duplicate   :: !( MenuItem Duplicate NoSubresource rt )
-  , delete      :: !( MenuItem Delete    NoSubresource rt )
-  , editSep2    :: !( Separator rt )
-  , preferences :: !( MenuItem ()        NoSubresource rt )
+  { undo           :: !( MenuItem Undo           NoSubresource rt )
+  , redo           :: !( MenuItem Redo           NoSubresource rt )
+  , discardChanges :: !( MenuItem DiscardChanges NoSubresource rt )
+  , editSep1       :: !( Separator rt )
+  , cut            :: !( MenuItem Cut            NoSubresource rt )
+  , copy           :: !( MenuItem Copy           NoSubresource rt )
+  , paste          :: !( MenuItem Paste          NoSubresource rt )
+  , duplicate      :: !( MenuItem Duplicate      NoSubresource rt )
+  , delete         :: !( MenuItem Delete         NoSubresource rt )
+  , editSep2       :: !( Separator rt )
+  , preferences    :: !( MenuItem ()             NoSubresource rt )
   }
   deriving stock Generic
 
@@ -191,16 +192,17 @@ fileMenuDescription
 editMenuDescription :: EditMenu Description
 editMenuDescription
   = EditMenu
-  { undo        = MenuItemDescription  "Undo"        [ "submenuItem" ] Undo      ( Just ( GDK.KEY_Z, [ Control L ] ) ) NoSubresource
-  , redo        = MenuItemDescription  "Redo"        [ "submenuItem" ] Redo      ( Just ( GDK.KEY_Y, [ Control L ] ) ) NoSubresource
-  , editSep1    = SeparatorDescription               [ "submenuSeparator" ]
-  , cut         = MenuItemDescription  "Cut"         [ "submenuItem" ] Cut       ( Just ( GDK.KEY_X, [ Control L ] ) ) NoSubresource
-  , copy        = MenuItemDescription  "Copy"        [ "submenuItem" ] Copy      ( Just ( GDK.KEY_C, [ Control L ] ) ) NoSubresource
-  , paste       = MenuItemDescription  "Paste"       [ "submenuItem" ] Paste     ( Just ( GDK.KEY_V, [ Control L ] ) ) NoSubresource
-  , duplicate   = MenuItemDescription  "Duplicate"   [ "submenuItem" ] Duplicate ( Just ( GDK.KEY_D, [ Control L ] ) ) NoSubresource
-  , delete      = MenuItemDescription  "Delete"      [ "submenuItem" ] Delete    ( Just ( GDK.KEY_Delete, [] ) )       NoSubresource
-  , editSep2    = SeparatorDescription               [ "submenuSeparator" ]
-  , preferences = MenuItemDescription  "Preferences" [ "submenuItem" ] ()        ( Just ( GDK.KEY_P, [ Control L, Shift L ] ) ) NoSubresource
+  { undo           = MenuItemDescription  "Undo"            [ "submenuItem" ] Undo           ( Just ( GDK.KEY_Z, [ Control L ] ) ) NoSubresource
+  , redo           = MenuItemDescription  "Redo"            [ "submenuItem" ] Redo           ( Just ( GDK.KEY_Y, [ Control L ] ) ) NoSubresource
+  , discardChanges = MenuItemDescription  "Discard changes" [ "submenuItem" ] DiscardChanges ( Just ( GDK.KEY_Z, [ Control L, Shift L ] ) ) NoSubresource
+  , editSep1       = SeparatorDescription                   [ "submenuSeparator" ]
+  , cut            = MenuItemDescription  "Cut"             [ "submenuItem" ] Cut       ( Just ( GDK.KEY_X, [ Control L ] ) ) NoSubresource
+  , copy           = MenuItemDescription  "Copy"            [ "submenuItem" ] Copy      ( Just ( GDK.KEY_C, [ Control L ] ) ) NoSubresource
+  , paste          = MenuItemDescription  "Paste"           [ "submenuItem" ] Paste     ( Just ( GDK.KEY_V, [ Control L ] ) ) NoSubresource
+  , duplicate      = MenuItemDescription  "Duplicate"       [ "submenuItem" ] Duplicate ( Just ( GDK.KEY_D, [ Control L ] ) ) NoSubresource
+  , delete         = MenuItemDescription  "Delete"          [ "submenuItem" ] Delete    ( Just ( GDK.KEY_Delete, [] ) )       NoSubresource
+  , editSep2       = SeparatorDescription                   [ "submenuSeparator" ]
+  , preferences    = MenuItemDescription  "Preferences"     [ "submenuItem" ] ()        ( Just ( GDK.KEY_P, [ Control L, Shift L ] ) ) NoSubresource
   }
 
 viewMenuDescription :: ViewMenu Description
diff --git a/src/lib/Math/Bezier/Stroke.hs b/src/lib/Math/Bezier/Stroke.hs
index a854d22..fe7c744 100644
--- a/src/lib/Math/Bezier/Stroke.hs
+++ b/src/lib/Math/Bezier/Stroke.hs
@@ -113,9 +113,13 @@ stroke Empty = Left Empty
 stroke ( spt0 :<| Empty ) = Left . removePointData $ ( Point2D 0 0 --> coords spt0 :: Vector2D Double ) • brushShape @x spt0
 stroke allPts@( spt0 :<| spt1 :<| spts )
   | isClosed
-  = Right ( fwdPts, bwdPts )
+  = if null ( brushShape @x spt0 )
+    then Right ( Empty, Empty )
+    else Right ( fwdPts, bwdPts )
   | otherwise
-  = Left ( startingCap <> fwdPts <> bwdPts )
+  = if   null ( brushShape @x spt0 )
+    then Left Empty
+    else Left ( startingCap <> fwdPts <> bwdPts )
   where
 
     startOffset, endOffset :: Vector2D Double
@@ -124,9 +128,9 @@ stroke allPts@( spt0 :<| spt1 :<| spts )
     startOffset = Point2D 0 0 --> coords spt0
     tgt_start = coords spt0 --> coords spt1
     ( tgt_end, endOffset, brush_end ) = case allPts of
-      _ :|> sptnm1 :|> sptn -> ( coords sptnm1 --> coords sptn, Point2D 0 0 --> coords sptn, brushShape sptn )
+      _ :|> sptnm1 :|> sptn -> ( coords sptnm1 --> coords sptn, Point2D 0 0 --> coords sptn, brushShape @x sptn )
       _                     -> error "impossible"
-    brush_start = brushShape spt0
+    brush_start = brushShape @x spt0
 
     isClosed :: Bool
     isClosed = case ( spt1 :<| spts ) of