Fix item selection after merge

Issue: #1809

modules/webapp/src/main/elm/Comp/ItemMerge.elm

@@ -105,7 +105,7 @@ type alias Action =
 
 type Outcome
     = OutcomeCancel
-    | OutcomeActionDone
+    | OutcomeActionDone (Maybe ItemLight)
     | OutcomeNotYet
 
 
@@ -148,7 +148,7 @@ update _ action msg model =
             if result.success then
                 { model = { model | formState = FormStateActionSuccessful }
                 , cmd = Cmd.none
-                , outcome = OutcomeActionDone
+                , outcome = OutcomeActionDone (List.head model.items)
                 }
 
             else

modules/webapp/src/main/elm/Data/ItemIds.elm

@@ -17,8 +17,10 @@ module Data.ItemIds exposing
     , fromSet
     , isEmpty
     , isMember
+    , maybeOne
     , noChange
     , nonEmpty
+    , one
     , select
     , selectAll
     , size
@@ -66,6 +68,16 @@ fromSet ids =
     ItemIds ids
 
 
+one : String -> ItemIds
+one id =
+    ItemIds (Set.singleton id)
+
+
+maybeOne : Maybe String -> ItemIds
+maybeOne id =
+    Maybe.map one id |> Maybe.withDefault empty
+
+
 union : ItemIds -> ItemIds -> ItemIds
 union (ItemIds ids1) (ItemIds ids2) =
     ItemIds (Set.union ids1 ids2)

modules/webapp/src/main/elm/Page/Search/Update.elm

@@ -620,21 +620,22 @@ update texts bookmarkId lastViewedItemId env msg model =
                                 Comp.ItemMerge.OutcomeNotYet ->
                                     SelectView { svm | mergeModel = createModel result.model }
 
-                                Comp.ItemMerge.OutcomeActionDone ->
+                                Comp.ItemMerge.OutcomeActionDone _ ->
                                     SearchView
 
                         model_ =
                             { model | viewMode = nextView }
                     in
-                    if result.outcome == Comp.ItemMerge.OutcomeActionDone then
+                    case result.outcome of
+                        Comp.ItemMerge.OutcomeActionDone target ->
                             update texts
                                 bookmarkId
                                 lastViewedItemId
-                            env
+                                { env | selectedItems = Data.ItemIds.maybeOne <| Maybe.map .id target }
                                 (DoSearch model.searchTypeDropdownValue)
                                 model_
 
-                    else
+                        _ ->
                             resultModelCmd env.selectedItems
                                 ( model_
                                 , Cmd.map MergeItemsMsg result.cmd