Fix crash when revoke root permission

app/src/main/java/com/topjohnwu/magisk/databinding/DiffObservableList.kt

@@ -6,12 +6,35 @@ import androidx.databinding.ListChangeRegistry
 import androidx.databinding.ObservableList
 import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.ListUpdateCallback
+import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import java.util.AbstractList
 
-open class DiffObservableList<T : DiffItem<*>>
+// Only expose the immutable List types
-    : AbstractList<T>(), ObservableList<T>, ListUpdateCallback {
+interface DiffList<T : DiffItem<*>> : List<T> {
+    fun calculateDiff(newItems: List<T>): DiffUtil.DiffResult
+
+    @MainThread
+    fun update(newItems: List<T>, diffResult: DiffUtil.DiffResult)
+
+    @WorkerThread
+    suspend fun update(newItems: List<T>)
+}
+
+interface FilterList<T : DiffItem<*>> : DiffList<T> {
+    fun filter(filter: (T) -> Boolean)
+}
+
+fun <T : DiffItem<*>> diffList(): DiffList<T> = DiffObservableList()
+
+fun <T : DiffItem<*>> filterList(scope: CoroutineScope): FilterList<T> =
+    FilterableDiffObservableList(scope)
+
+private open class DiffObservableList<T : DiffItem<*>>
+    : AbstractList<T>(), ObservableList<T>, DiffList<T>, ListUpdateCallback {
 
     protected var list: List<T> = emptyList()
         private set
@@ -21,7 +44,7 @@ open class DiffObservableList<T : DiffItem<*>>
 
     override fun get(index: Int) = list[index]
 
-    fun calculateDiff(newItems: List<T>): DiffUtil.DiffResult {
+    override fun calculateDiff(newItems: List<T>): DiffUtil.DiffResult {
         return doCalculateDiff(list, newItems)
     }
 
@@ -48,13 +71,13 @@ open class DiffObservableList<T : DiffItem<*>>
     }
 
     @MainThread
-    fun update(newItems: List<T>, diffResult: DiffUtil.DiffResult) {
+    override fun update(newItems: List<T>, diffResult: DiffUtil.DiffResult) {
         list = ArrayList(newItems)
         diffResult.dispatchUpdatesTo(this)
     }
 
     @WorkerThread
-    suspend fun update(newItems: List<T>) {
+    override suspend fun update(newItems: List<T>) {
         val diffResult = calculateDiff(newItems)
         withContext(Dispatchers.Main) {
             update(newItems, diffResult)
@@ -87,3 +110,35 @@ open class DiffObservableList<T : DiffItem<*>>
         listeners.notifyRemoved(this, position, count)
     }
 }
+
+private class FilterableDiffObservableList<T : DiffItem<*>>(
+    private val scope: CoroutineScope
+) : DiffObservableList<T>(), FilterList<T> {
+
+    private var sublist: List<T> = emptyList()
+    private var job: Job? = null
+
+    // ---
+
+    override fun filter(filter: (T) -> Boolean) {
+        job?.cancel()
+        job = scope.launch(Dispatchers.Default) {
+            val oldList = sublist
+            val newList = list.filter(filter)
+            val diff = doCalculateDiff(oldList, newList)
+            withContext(Dispatchers.Main) {
+                sublist = newList
+                diff.dispatchUpdatesTo(this@FilterableDiffObservableList)
+            }
+        }
+    }
+
+    // ---
+
+    override fun get(index: Int): T {
+        return sublist[index]
+    }
+
+    override val size: Int
+        get() = sublist.size
+}

app/src/main/java/com/topjohnwu/magisk/databinding/FilterableDiffObservableList.kt

@@ -1,39 +0,0 @@
-package com.topjohnwu.magisk.databinding
-
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.Job
-import kotlinx.coroutines.launch
-import kotlinx.coroutines.withContext
-
-open class FilterableDiffObservableList<T : DiffItem<*>>(
-    private val scope: CoroutineScope
-) : DiffObservableList<T>() {
-
-    private var sublist: List<T> = emptyList()
-    private var job: Job? = null
-
-    // ---
-
-    fun filter(filter: (T) -> Boolean) {
-        job?.cancel()
-        job = scope.launch(Dispatchers.Default) {
-            val oldList = sublist
-            val newList = list.filter(filter)
-            val diff = doCalculateDiff(oldList, newList)
-            withContext(Dispatchers.Main) {
-                sublist = newList
-                diff.dispatchUpdatesTo(this@FilterableDiffObservableList)
-            }
-        }
-    }
-
-    // ---
-
-    override fun get(index: Int): T {
-        return sublist[index]
-    }
-
-    override val size: Int
-        get() = sublist.size
-}

app/src/main/java/com/topjohnwu/magisk/databinding/MergeObservableList.kt

@@ -46,11 +46,11 @@ class MergeObservableList<T> : AbstractList<T>(), ObservableList<T> {
         return this
     }
 
-    fun insertList(list: ObservableList<out T>): MergeObservableList<T> {
+    fun insertList(list: List<T>): MergeObservableList<T> {
         val idx = size
         lists.add(list)
         ++modCount
-        (list as ObservableList<T>).addOnListChangedCallback(callback)
+        (list as? ObservableList<T>)?.addOnListChangedCallback(callback)
         if (list.isNotEmpty())
             listeners.notifyInserted(this, idx, list.size)
         return this
@@ -72,11 +72,11 @@ class MergeObservableList<T> : AbstractList<T>(), ObservableList<T> {
         return false
     }
 
-    fun removeList(listToRemove: ObservableList<out T>): Boolean {
+    fun removeList(listToRemove: List<T>): Boolean {
         var idx = 0
         for ((i, list) in lists.withIndex()) {
             if (listToRemove === list) {
-                (list as ObservableList<T>).removeOnListChangedCallback(callback)
+                (list as? ObservableList<T>)?.removeOnListChangedCallback(callback)
                 lists.removeAt(i)
                 ++modCount
                 listeners.notifyRemoved(this, idx, list.size)
@@ -90,8 +90,8 @@ class MergeObservableList<T> : AbstractList<T>(), ObservableList<T> {
     override fun clear() {
         val sz = size
         for (list in lists) {
-            if (list is ObservableList<*>) {
+            if (list is ObservableList) {
-                (list as ObservableList<T>).removeOnListChangedCallback(callback)
+                list.removeOnListChangedCallback(callback)
             }
         }
         ++modCount

app/src/main/java/com/topjohnwu/magisk/ui/deny/DenyListViewModel.kt

@@ -8,8 +8,8 @@ import com.topjohnwu.magisk.BR
 import com.topjohnwu.magisk.arch.AsyncLoadViewModel
 import com.topjohnwu.magisk.core.di.AppContext
 import com.topjohnwu.magisk.core.ktx.concurrentMap
-import com.topjohnwu.magisk.databinding.FilterableDiffObservableList
 import com.topjohnwu.magisk.databinding.bindExtra
+import com.topjohnwu.magisk.databinding.filterList
 import com.topjohnwu.magisk.databinding.set
 import com.topjohnwu.superuser.Shell
 import kotlinx.coroutines.Dispatchers
@@ -38,7 +38,7 @@ class DenyListViewModel : AsyncLoadViewModel() {
             query()
         }
 
-    val items = FilterableDiffObservableList<DenyListRvItem>(viewModelScope)
+    val items = filterList<DenyListRvItem>(viewModelScope)
     val extraBindings = bindExtra {
         it.put(BR.viewModel, this)
     }

app/src/main/java/com/topjohnwu/magisk/ui/log/LogViewModel.kt

@@ -13,8 +13,8 @@ import com.topjohnwu.magisk.core.ktx.toTime
 import com.topjohnwu.magisk.core.repository.LogRepository
 import com.topjohnwu.magisk.core.utils.MediaStoreUtils
 import com.topjohnwu.magisk.core.utils.MediaStoreUtils.outputStream
-import com.topjohnwu.magisk.databinding.DiffObservableList
 import com.topjohnwu.magisk.databinding.bindExtra
+import com.topjohnwu.magisk.databinding.diffList
 import com.topjohnwu.magisk.databinding.set
 import com.topjohnwu.magisk.events.SnackbarEvent
 import com.topjohnwu.magisk.view.TextItem
@@ -37,13 +37,13 @@ class LogViewModel(
 
     // --- su log
 
-    val items = DiffObservableList<SuLogRvItem>()
+    val items = diffList<SuLogRvItem>()
     val extraBindings = bindExtra {
         it.put(BR.viewModel, this)
     }
 
     // --- magisk log
-    val logs = DiffObservableList<LogRvItem>()
+    val logs = diffList<LogRvItem>()
     var magiskLogRaw = " "
 
     override suspend fun doLoadWork() {

app/src/main/java/com/topjohnwu/magisk/ui/module/ModuleViewModel.kt

@@ -10,10 +10,10 @@ import com.topjohnwu.magisk.core.Info
 import com.topjohnwu.magisk.core.base.ContentResultCallback
 import com.topjohnwu.magisk.core.model.module.LocalModule
 import com.topjohnwu.magisk.core.model.module.OnlineModule
-import com.topjohnwu.magisk.databinding.DiffObservableList
 import com.topjohnwu.magisk.databinding.MergeObservableList
 import com.topjohnwu.magisk.databinding.RvItem
 import com.topjohnwu.magisk.databinding.bindExtra
+import com.topjohnwu.magisk.databinding.diffList
 import com.topjohnwu.magisk.databinding.set
 import com.topjohnwu.magisk.dialog.LocalModuleInstallDialog
 import com.topjohnwu.magisk.dialog.OnlineModuleInstallDialog
@@ -27,7 +27,7 @@ class ModuleViewModel : AsyncLoadViewModel() {
 
     val bottomBarBarrierIds = intArrayOf(R.id.module_update, R.id.module_remove)
 
-    private val itemsInstalled = DiffObservableList<LocalModuleRvItem>()
+    private val itemsInstalled = diffList<LocalModuleRvItem>()
 
     val items = MergeObservableList<RvItem>()
     val extraBindings = bindExtra {

app/src/main/java/com/topjohnwu/magisk/ui/superuser/SuperuserViewModel.kt

@@ -34,7 +34,7 @@ class SuperuserViewModel(
     private val itemNoData = TextItem(R.string.superuser_policy_none)
 
     private val itemsHelpers = ObservableArrayList<TextItem>()
-    private val itemsPolicies = DiffObservableList<PolicyRvItem>()
+    private val itemsPolicies = diffList<PolicyRvItem>()
 
     val items = MergeObservableList<RvItem>()
         .insertList(itemsHelpers)
@@ -105,8 +105,10 @@ class SuperuserViewModel(
     fun deletePressed(item: PolicyRvItem) {
         fun updateState() = viewModelScope.launch {
             db.delete(item.item.uid)
-            itemsPolicies.removeAll { it.itemSameAs(item) }
+            val list = ArrayList(itemsPolicies)
-            if (itemsPolicies.isEmpty() && itemsHelpers.isEmpty()) {
+            list.removeAll { it.itemSameAs(item) }
+            itemsPolicies.update(list)
+            if (list.isEmpty() && itemsHelpers.isEmpty()) {
                 itemsHelpers.add(itemNoData)
             }
         }