Fix #373 and a few crashes

app/src/main/java/eu/kanade/tachiyomi/ui/base/activity/ActivityMixin.kt

@@ -15,11 +15,17 @@ import uy.kohesive.injekt.api.get
 
 interface ActivityMixin {
 
+    var resumed: Boolean
+
     fun setupToolbar(toolbar: Toolbar, backNavigation: Boolean = true) {
         setSupportActionBar(toolbar)
         getSupportActionBar()?.setDisplayHomeAsUpEnabled(true)
         if (backNavigation) {
-            toolbar.setNavigationOnClickListener { onBackPressed() }
+            toolbar.setNavigationOnClickListener {
+                if (resumed) {
+                    onBackPressed()
+                }
+            }
         }
     }
 

app/src/main/java/eu/kanade/tachiyomi/ui/base/activity/BaseActivity.kt

@@ -5,15 +5,14 @@ import eu.kanade.tachiyomi.util.LocaleHelper
 
 abstract class BaseActivity : AppCompatActivity(), ActivityMixin {
 
+    override var resumed = false
+
     init {
         LocaleHelper.updateConfiguration(this)
     }
 
     override fun getActivity() = this
 
-    var resumed = false
-        private set
-
     override fun onResume() {
         super.onResume()
         resumed = true

app/src/main/java/eu/kanade/tachiyomi/ui/base/activity/BaseRxActivity.kt

@@ -8,6 +8,8 @@ import nucleus.view.NucleusAppCompatActivity
 
 abstract class BaseRxActivity<P : BasePresenter<*>> : NucleusAppCompatActivity<P>(), ActivityMixin {
 
+    override var resumed = false
+
     init {
         LocaleHelper.updateConfiguration(this)
     }
@@ -25,9 +27,6 @@ abstract class BaseRxActivity<P : BasePresenter<*>> : NucleusAppCompatActivity<P
 
     override fun getActivity() = this
 
-    var resumed = false
-        private set
-
     override fun onResume() {
         super.onResume()
         resumed = true