Fix up navigation button behavior

app/src/main/kotlin/org/koitharu/kotatsu/core/ui/BaseActivity.kt

@@ -3,6 +3,7 @@ package org.koitharu.kotatsu.core.ui
 import android.content.Intent
 import android.content.res.Configuration
 import android.graphics.Color
+import android.os.Build
 import android.os.Bundle
 import android.view.KeyEvent
 import android.view.View
@@ -92,9 +93,22 @@ abstract class BaseActivity<B : ViewBinding> :
 	}
 
 	override fun onSupportNavigateUp(): Boolean {
+		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
+			// TODO fix behavior on Android 14
 			dispatchNavigateUp()
 			return true
 		}
+		val fm = supportFragmentManager
+		if (fm.isStateSaved) {
+			return false
+		}
+		if (fm.backStackEntryCount > 0) {
+			fm.popBackStack()
+		} else {
+			dispatchNavigateUp()
+		}
+		return true
+	}
 
 	override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean {
 		if (BuildConfig.DEBUG && keyCode == KeyEvent.KEYCODE_VOLUME_UP) {

app/src/main/kotlin/org/koitharu/kotatsu/tracker/domain/Tracker.kt

@@ -30,10 +30,6 @@ class Tracker @Inject constructor(
 		return repository.getTracks(offset = 0, limit = limit)
 	}
 
-	suspend fun gc() {
-		repository.gc()
-	}
-
 	suspend fun fetchUpdates(
 		track: MangaTracking,
 		commit: Boolean