Check for empty sender on block sender rule

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

@@ -609,9 +609,15 @@ public class EntityRule {
     }
 
     static EntityRule blockSender(Context context, EntityMessage message, EntityFolder junk, boolean block_domain, List<String> whitelist) throws JSONException {
+        if (message.from == null || message.from.length == 0)
+            return null;
+
         String sender = ((InternetAddress) message.from[0]).getAddress();
         String name = MessageHelper.formatAddresses(new Address[]{message.from[0]});
 
+        if (TextUtils.isEmpty(sender))
+            return null;
+
         if (block_domain) {
             int at = sender.indexOf('@');
             if (at > 0) {

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

@@ -6330,10 +6330,10 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
 
                     EntityOperation.queue(context, message, EntityOperation.MOVE, junk.id);
 
-                    if ((block_sender || block_domain) &&
-                            (message.from != null && message.from.length > 0)) {
+                    if (block_sender || block_domain) {
                         EntityRule rule = EntityRule.blockSender(context, message, junk, block_domain, whitelist);
-                        rule.id = db.rule().insertRule(rule);
+                        if (rule != null)
+                            rule.id = db.rule().insertRule(rule);
                     }
 
 

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

@@ -262,7 +262,8 @@ public class ServiceUI extends IntentService {
 
             if (block_sender) {
                 EntityRule rule = EntityRule.blockSender(this, message, junk, false, whitelist);
-                rule.id = db.rule().insertRule(rule);
+                if (rule != null)
+                    rule.id = db.rule().insertRule(rule);
             }
 
             db.setTransactionSuccessful();