Fixes

app/src/main/java/org/koitharu/kotatsu/details/ui/ChaptersFragment.kt

@@ -7,6 +7,10 @@ import android.widget.AdapterView
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.view.ActionMode
 import androidx.core.graphics.Insets
+import androidx.core.view.isVisible
+import androidx.core.view.updatePadding
+import androidx.recyclerview.widget.DividerItemDecoration
+import androidx.recyclerview.widget.RecyclerView
 import org.koin.androidx.viewmodel.ext.android.sharedViewModel
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.base.ui.BaseFragment
@@ -46,7 +50,12 @@ class ChaptersFragment : BaseFragment<FragmentChaptersBinding>(),
 		chaptersAdapter = ChaptersAdapter(this)
 		selectionDecoration = ChaptersSelectionDecoration(view.context)
 		with(binding.recyclerViewChapters) {
-			addItemDecoration(DividerItemDecoration(view.context, RecyclerView.VERTICAL))
+			addItemDecoration(
+				DividerItemDecoration(
+					view.context,
+					RecyclerView.VERTICAL
+				)
+			)
 			addItemDecoration(selectionDecoration!!)
 			setHasFixedSize(true)
 			adapter = chaptersAdapter

app/src/main/java/org/koitharu/kotatsu/favourites/ui/FavouritesPagerAdapter.kt

@@ -25,6 +25,14 @@ class FavouritesPagerAdapter(
 		return FavouritesListFragment.newInstance(item.id)
 	}
 
+	override fun getItemId(position: Int): Long {
+		return differ.currentList[position].id
+	}
+
+	override fun containsItem(itemId: Long): Boolean {
+		return differ.currentList.any { it.id == itemId }
+	}
+
 	override fun onConfigureTab(tab: TabLayout.Tab, position: Int) {
 		val item = differ.currentList[position]
 		tab.text = item.title

app/src/main/java/org/koitharu/kotatsu/local/data/MangaIndex.kt

@@ -72,6 +72,7 @@ class MangaIndex(source: String?) {
 			jo.put("number", chapter.number)
 			jo.put("url", chapter.url)
 			jo.put("name", chapter.name)
+			jo.put("branch", chapter.branch)
 			jo.put("entries", "%03d\\d{3}".format(chapter.number))
 			chapters.put(chapter.id.toString(), jo)
 		}
@@ -97,6 +98,7 @@ class MangaIndex(source: String?) {
 					name = v.getString("name"),
 					url = v.getString("url"),
 					number = v.getInt("number"),
+					branch = v.getStringOrNull("branch"),
 					source = source
 				)
 			)

app/src/main/java/org/koitharu/kotatsu/reader/ui/pager/BaseReaderAdapter.kt

@@ -21,6 +21,7 @@ abstract class BaseReaderAdapter<H : BasePageHolder<*>>(
 
 	init {
 		setHasStableIds(true)
+		stateRestorationPolicy = StateRestorationPolicy.PREVENT
 	}
 
 	override fun onBindViewHolder(holder: H, position: Int) {

app/src/main/res/layout/fragment_chapters.xml

@@ -1,33 +1,30 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.coordinatorlayout.widget.CoordinatorLayout
+<RelativeLayout
 	xmlns:android="http://schemas.android.com/apk/res/android"
 	xmlns:app="http://schemas.android.com/apk/res-auto"
 	xmlns:tools="http://schemas.android.com/tools"
 	android:layout_width="match_parent"
 	android:layout_height="match_parent">
 
-	<com.google.android.material.appbar.AppBarLayout
-		android:id="@+id/app_bar"
-		style="@style/Widget.MaterialComponents.AppBarLayout.Surface"
-		android:layout_width="match_parent"
+	<Spinner
+		android:id="@+id/spinner_branches"
+		android:layout_width="0dp"
 		android:layout_height="wrap_content"
-		app:layout_behavior="com.google.android.material.appbar.AppBarLayout$Behavior">
-
-		<Spinner
-			android:id="@+id/spinner_branches"
-			android:layout_width="match_parent"
-			android:layout_height="wrap_content"
-			android:visibility="gone"
-			app:layout_scrollFlags="scroll|enterAlways"
-			tools:listitem="@layout/item_branch"
-			tools:visibility="visible" />
-
-	</com.google.android.material.appbar.AppBarLayout>
+		android:layout_alignParentStart="true"
+		android:layout_alignParentTop="true"
+		android:layout_alignParentEnd="true"
+		android:visibility="gone"
+		tools:listitem="@layout/item_branch" />
 
 	<androidx.recyclerview.widget.RecyclerView
 		android:id="@+id/recyclerView_chapters"
-		android:layout_width="match_parent"
-		android:layout_height="match_parent"
+		android:layout_width="0dp"
+		android:layout_height="0dp"
+		android:layout_alignWithParentIfMissing="true"
+		android:layout_below="@id/spinner_branches"
+		android:layout_alignParentStart="true"
+		android:layout_alignParentEnd="true"
+		android:layout_alignParentBottom="true"
 		android:orientation="vertical"
 		android:scrollbars="vertical"
 		app:fastScrollEnabled="true"
@@ -36,7 +33,6 @@
 		app:fastScrollVerticalThumbDrawable="@drawable/list_thumb"
 		app:fastScrollVerticalTrackDrawable="@drawable/list_track"
 		app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
-		app:layout_behavior="com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior"
 		tools:listitem="@layout/item_chapter" />
 
 	<ProgressBar
@@ -44,8 +40,9 @@
 		style="@style/Widget.AppCompat.ProgressBar"
 		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
+		android:layout_centerInParent="true"
 		android:layout_gravity="center"
 		android:visibility="gone"
 		tools:visibility="visible" />
 
-</androidx.coordinatorlayout.widget.CoordinatorLayout>
+</RelativeLayout>