Be more rigorous about discerning media message thread.

Fixes #4312
// FREEBIE

src/org/thoughtcrime/securesms/database/MmsDatabase.java

@@ -59,6 +59,7 @@ import org.thoughtcrime.securesms.recipients.RecipientFormattingException;
 import org.thoughtcrime.securesms.recipients.Recipients;
 import org.thoughtcrime.securesms.util.GroupUtil;
 import org.thoughtcrime.securesms.util.JsonUtils;
+import org.thoughtcrime.securesms.util.ServiceUtil;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import org.thoughtcrime.securesms.util.Util;
 import org.whispersystems.jobqueue.JobManager;
@@ -252,6 +253,7 @@ public class MmsDatabase extends MessagingDatabase {
       return DatabaseFactory.getThreadDatabase(context).getThreadIdFor(groupRecipients);
     }
 
+    String      localNumber;
     Set<String> group       = new HashSet<>();
 
     if (retrieved.getAddresses().getFrom() == null) {
@@ -260,11 +262,10 @@ public class MmsDatabase extends MessagingDatabase {
 
     group.add(retrieved.getAddresses().getFrom());
 
-      TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
+    if (TextSecurePreferences.isPushRegistered(context)) {
-      String           localNumber      = telephonyManager.getLine1Number();
-
-      if (localNumber == null) {
       localNumber = TextSecurePreferences.getLocalNumber(context);
+    } else {
+      localNumber = ServiceUtil.getTelephonyManager(context).getLine1Number();
     }
 
     for (String cc : retrieved.getAddresses().getCc()) {
@@ -280,6 +281,8 @@ public class MmsDatabase extends MessagingDatabase {
       }
     }
 
+
+    if (retrieved.getAddresses().getTo().size() > 1) {
       for (String to : retrieved.getAddresses().getTo()) {
         PhoneNumberUtil.MatchType match;
 
@@ -291,10 +294,13 @@ public class MmsDatabase extends MessagingDatabase {
         {
           group.add(to);
         }
+
+      }
     }
 
     String     recipientsList = Util.join(group, ",");
     Recipients recipients     = RecipientFactory.getRecipientsFromString(context, recipientsList, false);
+
     return DatabaseFactory.getThreadDatabase(context).getThreadIdFor(recipients);
   }
 

src/org/thoughtcrime/securesms/util/ServiceUtil.java

@@ -4,6 +4,7 @@ import android.app.Activity;
 import android.app.NotificationManager;
 import android.content.Context;
 import android.net.ConnectivityManager;
+import android.telephony.TelephonyManager;
 import android.view.WindowManager;
 import android.view.inputmethod.InputMethodManager;
 
@@ -23,4 +24,8 @@ public class ServiceUtil {
   public static NotificationManager getNotificationManager(Context context) {
     return (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
   }
+
+  public static TelephonyManager getTelephonyManager(Context context) {
+    return (TelephonyManager)context.getSystemService(Context.TELEPHONY_SERVICE);
+  }
 }