Crash fixes

app/src/main/java/eu/kanade/mangafeed/data/cache/CoverCache.java

@@ -1,6 +1,7 @@
 package eu.kanade.mangafeed.data.cache;
 
 import android.content.Context;
+import android.text.TextUtils;
 import android.widget.ImageView;
 
 import com.bumptech.glide.Glide;
@@ -43,6 +44,9 @@ public class CoverCache {
     // Download the cover with Glide (it can avoid repeating requests) and save the file on this cache
     // Optionally, load the image in the given image view when the resource is ready, if not null
     public void save(String thumbnailUrl, LazyHeaders headers, ImageView imageView) {
+        if (TextUtils.isEmpty(thumbnailUrl))
+            return;
+
         GlideUrl url = new GlideUrl(thumbnailUrl, headers);
         Glide.with(context)
                 .load(url)
@@ -93,6 +97,9 @@ public class CoverCache {
 
     // Delete the cover from cache
     public boolean delete(String thumbnailUrl) {
+        if (TextUtils.isEmpty(thumbnailUrl))
+            return false;
+
         File file = new File(cacheDir, DiskUtils.hashKeyForDisk(thumbnailUrl));
         return file.exists() && file.delete();
     }

app/src/main/java/eu/kanade/mangafeed/ui/catalogue/CataloguePresenter.java

@@ -4,7 +4,6 @@ import android.os.Bundle;
 import android.text.TextUtils;
 import android.util.Pair;
 
-import com.bumptech.glide.Glide;
 import com.pushtorefresh.storio.sqlite.operations.put.PutResult;
 
 import java.util.List;
@@ -20,6 +19,7 @@ import eu.kanade.mangafeed.data.source.base.Source;
 import eu.kanade.mangafeed.data.source.model.MangasPage;
 import eu.kanade.mangafeed.ui.base.presenter.BasePresenter;
 import eu.kanade.mangafeed.util.RxPager;
+import icepick.State;
 import rx.Observable;
 import rx.android.schedulers.AndroidSchedulers;
 import rx.schedulers.Schedulers;
@@ -34,6 +34,7 @@ public class CataloguePresenter extends BasePresenter<CatalogueFragment> {
     @Inject PreferencesHelper prefs;
 
     private Source source;
+    @State int sourceId;
 
     private String query;
 
@@ -78,19 +79,14 @@ public class CataloguePresenter extends BasePresenter<CatalogueFragment> {
     }
 
     private void onProcessRestart() {
+        source = sourceManager.get(sourceId);
         stop(GET_MANGA_LIST);
         stop(GET_MANGA_DETAIL);
     }
 
-    @Override
-    protected void onDestroy() {
-        // Catalogue covers are probably not going to be needed for a long time
-        Glide.get(getContext()).clearMemory();
-        super.onDestroy();
-    }
-
     public void startRequesting(Source source) {
         this.source = source;
+        sourceId = source.getId();
         restartRequest(null);
     }
 

app/src/main/java/eu/kanade/mangafeed/ui/manga/chapter/ChaptersFragment.java

@@ -10,7 +10,6 @@ import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
 import android.view.LayoutInflater;
 import android.view.Menu;
-import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
@@ -62,12 +61,6 @@ public class ChaptersFragment extends BaseRxFragment<ChaptersPresenter> implemen
         return new ChaptersFragment();
     }
 
-    @Override
-    public void onCreate(Bundle savedState) {
-        super.onCreate(savedState);
-        setHasOptionsMenu(true);
-    }
-
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
                              Bundle savedInstanceState) {
@@ -122,22 +115,6 @@ public class ChaptersFragment extends BaseRxFragment<ChaptersPresenter> implemen
         super.onPause();
     }
 
-    @Override
-    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
-        inflater.inflate(R.menu.chapters, menu);
-        super.onCreateOptionsMenu(menu, inflater);
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        switch (item.getItemId()) {
-            case R.id.action_refresh:
-                fetchChapters();
-                break;
-        }
-        return super.onOptionsItemSelected(item);
-    }
-
     public void onNextChapters(List<Chapter> chapters) {
         // If the list is empty, fetch chapters from source if the conditions are met
         // We use presenter chapters instead because they are always unfiltered
@@ -156,8 +133,10 @@ public class ChaptersFragment extends BaseRxFragment<ChaptersPresenter> implemen
     }
 
     public void fetchChapters() {
-        swipeRefresh.setRefreshing(true);
-        getPresenter().fetchChaptersFromSource();
+        if (getPresenter().getManga() != null) {
+            swipeRefresh.setRefreshing(true);
+            getPresenter().fetchChaptersFromSource();
+        }
     }
 
     public void onFetchChaptersDone() {

app/src/main/java/eu/kanade/mangafeed/ui/manga/chapter/ChaptersPresenter.java

@@ -21,6 +21,7 @@ import eu.kanade.mangafeed.event.DownloadChaptersEvent;
 import eu.kanade.mangafeed.event.ReaderEvent;
 import eu.kanade.mangafeed.ui.base.presenter.BasePresenter;
 import eu.kanade.mangafeed.util.EventBusHook;
+import icepick.State;
 import rx.Observable;
 import rx.android.schedulers.AndroidSchedulers;
 import rx.schedulers.Schedulers;
@@ -40,7 +41,7 @@ public class ChaptersPresenter extends BasePresenter<ChaptersFragment> {
     private boolean sortOrderAToZ = true;
     private boolean onlyUnread = true;
     private boolean onlyDownloaded;
-    private boolean hasRequested;
+    @State boolean hasRequested;
 
     private PublishSubject<List<Chapter>> chaptersSubject;
 

app/src/main/java/eu/kanade/mangafeed/ui/reader/viewer/pager/PagerReader.java

@@ -25,7 +25,7 @@ public abstract class PagerReader extends BaseReader {
     protected void initializePager(Pager pager) {
         this.pager = pager;
         pager.setLayoutParams(new ViewGroup.LayoutParams(MATCH_PARENT, MATCH_PARENT));
-        pager.setOffscreenPageLimit(2);
+        pager.setOffscreenPageLimit(1);
         pager.setId(R.id.view_pager);
         pager.setOnChapterBoundariesOutListener(new OnChapterBoundariesOutListener() {
             @Override