fix various timeline related crashes (#2369)

* fix various timeline related crashes

* fix ktlint

app/src/main/java/com/keylesspalace/tusky/components/timeline/TimelineFragment.kt

@@ -217,7 +217,7 @@ class TimelineFragment :
             }
         })
 
-        lifecycleScope.launch {
+        viewLifecycleOwner.lifecycleScope.launch {
             viewModel.statuses.collectLatest { pagingData ->
                 adapter.submitData(pagingData)
             }
@@ -271,7 +271,11 @@ class TimelineFragment :
     private fun setupRecyclerView() {
         binding.recyclerView.setAccessibilityDelegateCompat(
             ListStatusAccessibilityDelegate(binding.recyclerView, this) { pos ->
-                adapter.peek(pos)
+                if (pos in 0 until adapter.itemCount) {
+                    adapter.peek(pos)
+                } else {
+                    null
+                }
             }
         )
         binding.recyclerView.setHasFixedSize(true)

app/src/main/java/com/keylesspalace/tusky/components/timeline/viewmodel/CachedTimelineViewModel.kt

@@ -70,7 +70,14 @@ class CachedTimelineViewModel @Inject constructor(
     override val statuses = Pager(
         config = PagingConfig(pageSize = LOAD_AT_ONCE),
         remoteMediator = CachedTimelineRemoteMediator(accountManager, api, db, gson),
-        pagingSourceFactory = { db.timelineDao().getStatuses(accountManager.activeAccount!!.id) }
+        pagingSourceFactory = {
+            val activeAccount = accountManager.activeAccount
+            if (activeAccount == null) {
+                EmptyTimelinePagingSource()
+            } else {
+                db.timelineDao().getStatuses(activeAccount.id)
+            }
+        }
     ).flow
         .map { pagingData ->
             pagingData.map { timelineStatus ->

app/src/main/java/com/keylesspalace/tusky/components/timeline/viewmodel/EmptyTimelinePagingSource.kt

@@ -0,0 +1,11 @@
+package com.keylesspalace.tusky.components.timeline.viewmodel
+
+import androidx.paging.PagingSource
+import androidx.paging.PagingState
+import com.keylesspalace.tusky.db.TimelineStatusWithAccount
+
+class EmptyTimelinePagingSource : PagingSource<Int, TimelineStatusWithAccount>() {
+    override fun getRefreshKey(state: PagingState<Int, TimelineStatusWithAccount>): Int? = null
+
+    override suspend fun load(params: LoadParams<Int>): LoadResult<Int, TimelineStatusWithAccount> = LoadResult.Page(emptyList(), null, null)
+}