vpop: Only update state after successful checkout

If checkout fails for some reason, they're still in a view, and should be
able to vpop again.

Command/VPop.hs

@@ -28,22 +28,29 @@ start ps = go =<< currentView
   where
 	go Nothing = giveup "Not in a view."
 	go (Just (v, madj)) = starting "vpop" ai si $ do
-		removeView v
-		(oldvs, vs) <- splitAt (num - 1) . filter (sameparentbranch v)
+		(oldvs, vs) <- splitAt (num - 1) 
+			. filter (sameparentbranch v)
+			. filter (/= v)
 			<$> recentViews
-		mapM_ removeView oldvs
-		case vs of
-			(oldv:_) -> next $ do
+		let removeview = mapM_ removeView (v : oldvs)
+		ok <- case vs of
+			(oldv:_) -> do
 				showOutput
 				checkoutViewBranch oldv madj
 					(\v' madj' -> return (branchView v' madj'))
-			_ -> next $ do
+			_ -> do
 				showOutput
 				inRepo $ Git.Command.runBool
 					[ Param "checkout"
 					, Param $ Git.fromRef $ Git.Ref.base $
 						viewParentBranch v
 					]
+		if ok
+			then
+				next $ do
+					removeview
+					return True
+			else next $ return False
 	sameparentbranch a b = viewParentBranch a == viewParentBranch b
 
 	num = fromMaybe 1 $ readish =<< headMaybe ps