Use standard charset name

app/src/main/java/eu/faircode/email/AdapterMessage.java

@@ -128,6 +128,7 @@ import java.io.File;
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.lang.reflect.Field;
+import java.nio.charset.StandardCharsets;
 import java.security.NoSuchAlgorithmException;
 import java.text.DateFormat;
 import java.text.NumberFormat;
@@ -1536,11 +1537,11 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                         tvBody.setTextIsSelectable(true);
                         tvBody.setMovementMethod(new TouchHandler(message));
                     } else if (result instanceof String)
-                        ((WebView) wvBody).loadDataWithBaseURL(null, (String) result, "text/html", "UTF-8", null);
+                        ((WebView) wvBody).loadDataWithBaseURL(null, (String) result, "text/html", StandardCharsets.UTF_8.name(), null);
                     else if (result == null) {
                         boolean show_full = args.getBoolean("show_full");
                         if (show_full)
-                            ((WebView) wvBody).loadDataWithBaseURL(null, "", "text/html", "UTF-8", null);
+                            ((WebView) wvBody).loadDataWithBaseURL(null, "", "text/html", StandardCharsets.UTF_8.name(), null);
                         else
                             tvBody.setText(null);
                     } else

app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java

@@ -38,6 +38,7 @@ import com.sun.mail.imap.protocol.IMAPResponse;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.text.Normalizer;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -332,7 +333,7 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
                                 } else {
                                     if (!protocol.supportsUtf8()) {
                                         arg.writeAtom("CHARSET");
-                                        arg.writeAtom("UTF-8");
+                                        arg.writeAtom(StandardCharsets.UTF_8.name());
                                     }
                                     if (keywords)
                                         arg.writeAtom("OR");

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -122,6 +122,7 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
 import java.text.Collator;
 import java.text.DateFormat;
 import java.text.NumberFormat;
@@ -4583,7 +4584,7 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
                     }
                 });
 
-                printWebView.loadDataWithBaseURL("about:blank", data[1], "text/html", "UTF-8", null);
+                printWebView.loadDataWithBaseURL("about:blank", data[1], "text/html", StandardCharsets.UTF_8.name(), null);
             }
 
             @Override

app/src/main/java/eu/faircode/email/ImageHelper.java

@@ -57,7 +57,10 @@ import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.net.HttpURLConnection;
 import java.net.URL;
+import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.concurrent.ExecutorService;
@@ -68,6 +71,8 @@ class ImageHelper {
     private static final ExecutorService executor =
             Helper.getBackgroundExecutor(1, "image");
 
+    private static final int MAX_REDIRECTS = 10;
+
     static Bitmap generateIdenticon(@NonNull String email, int size, int pixels, Context context) {
         byte[] hash = getHash(email);
         float h = Math.abs(email.hashCode()) % 360;
@@ -346,7 +351,43 @@ class ImageHelper {
                         }
 
                         Bitmap bm;
-                        try (BufferedInputStream is = new BufferedInputStream(new URL(a.source).openStream())) {
+                        HttpURLConnection urlConnection = null;
+                        try {
+                            String url = a.source;
+                            int redirects = 0;
+                            while (true) {
+                                urlConnection = (HttpURLConnection) new URL(url).openConnection();
+                                urlConnection.setRequestMethod("GET");
+                                urlConnection.setDoOutput(false);
+                                urlConnection.setInstanceFollowRedirects(true);
+                                urlConnection.connect();
+
+                                int status = urlConnection.getResponseCode();
+
+                                if (status == HttpURLConnection.HTTP_MOVED_PERM ||
+                                        status == HttpURLConnection.HTTP_MOVED_TEMP) {
+                                    redirects++;
+                                    if (redirects > MAX_REDIRECTS)
+                                        throw new IOException("Too many redirects");
+
+                                    String location = URLDecoder.decode(
+                                            urlConnection.getHeaderField("Location"),
+                                            StandardCharsets.UTF_8.name());
+                                    url = new URL(new URL(url), location).toExternalForm();
+                                    Log.i("Redirect #" + redirects + " to " + url);
+
+                                    urlConnection.disconnect();
+                                    continue;
+                                }
+
+                                if (status != HttpURLConnection.HTTP_OK)
+                                    throw new IOException("http " + status);
+
+                                break;
+                            }
+
+                            BufferedInputStream is = new BufferedInputStream(urlConnection.getInputStream());
+
                             Log.i("Probe " + a.source);
                             is.mark(8192);
                             BitmapFactory.Options options = new BitmapFactory.Options();
@@ -366,6 +407,9 @@ class ImageHelper {
                                 bm = BitmapFactory.decodeStream(is, null, options);
                             } else
                                 bm = BitmapFactory.decodeStream(is);
+                        } finally {
+                            if (urlConnection != null)
+                                urlConnection.disconnect();
                         }
 
                         if (bm == null)