do not load conversations with null jid

src/main/java/eu/siacs/conversations/entities/Conversation.java

@@ -23,6 +23,8 @@ import eu.siacs.conversations.Config;
 import eu.siacs.conversations.crypto.OmemoSetting;
 import eu.siacs.conversations.crypto.PgpDecryptionService;
 import eu.siacs.conversations.crypto.axolotl.AxolotlService;
+import eu.siacs.conversations.utils.JidHelper;
+import eu.siacs.conversations.xmpp.InvalidJid;
 import eu.siacs.conversations.xmpp.chatstate.ChatState;
 import eu.siacs.conversations.xmpp.mam.MamReference;
 import rocks.xmpp.addr.Jid;
@@ -104,18 +106,11 @@ public class Conversation extends AbstractEntity implements Blockable, Comparabl
 	}
 
 	public static Conversation fromCursor(Cursor cursor) {
-		Jid jid;
-		try {
-			jid = Jid.of(cursor.getString(cursor.getColumnIndex(CONTACTJID)));
-		} catch (final IllegalArgumentException e) {
-			// Borked DB..
-			jid = null;
-		}
 		return new Conversation(cursor.getString(cursor.getColumnIndex(UUID)),
 				cursor.getString(cursor.getColumnIndex(NAME)),
 				cursor.getString(cursor.getColumnIndex(CONTACT)),
 				cursor.getString(cursor.getColumnIndex(ACCOUNT)),
-				jid,
+				JidHelper.parseOrFallbackToInvalid(cursor.getString(cursor.getColumnIndex(CONTACTJID))),
 				cursor.getLong(cursor.getColumnIndex(CREATED)),
 				cursor.getInt(cursor.getColumnIndex(STATUS)),
 				cursor.getInt(cursor.getColumnIndex(MODE)),

src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java

@@ -53,6 +53,7 @@ import eu.siacs.conversations.utils.CryptoHelper;
 import eu.siacs.conversations.utils.FtsUtils;
 import eu.siacs.conversations.utils.MimeUtils;
 import eu.siacs.conversations.utils.Resolver;
+import eu.siacs.conversations.xmpp.InvalidJid;
 import eu.siacs.conversations.xmpp.mam.MamReference;
 import rocks.xmpp.addr.Jid;
 
@@ -680,10 +681,14 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		SQLiteDatabase db = this.getReadableDatabase();
 		String[] selectionArgs = {Integer.toString(status)};
 		Cursor cursor = db.rawQuery("select * from " + Conversation.TABLENAME
-				+ " where " + Conversation.STATUS + " = ? order by "
+				+ " where " + Conversation.STATUS + " = ? and "+Conversation.CONTACTJID+" is not null order by "
 				+ Conversation.CREATED + " desc", selectionArgs);
 		while (cursor.moveToNext()) {
-			list.add(Conversation.fromCursor(cursor));
+			final Conversation conversation = Conversation.fromCursor(cursor);
+			if (conversation.getJid() instanceof InvalidJid) {
+				continue;
+			}
+			list.add(conversation);
 		}
 		cursor.close();
 		return list;
@@ -780,6 +785,9 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 		cursor.moveToFirst();
 		Conversation conversation = Conversation.fromCursor(cursor);
 		cursor.close();
+		if (conversation.getJid() instanceof InvalidJid) {
+			return null;
+		}
 		return conversation;
 	}
 

src/main/java/eu/siacs/conversations/utils/JidHelper.java

@@ -34,6 +34,7 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
 
+import eu.siacs.conversations.xmpp.InvalidJid;
 import rocks.xmpp.addr.Jid;
 
 public class JidHelper {
@@ -50,4 +51,12 @@ public class JidHelper {
 		}
 	}
 
+	public static Jid parseOrFallbackToInvalid(String jid) {
+		try {
+			return Jid.of(jid);
+		} catch (IllegalArgumentException e) {
+			return InvalidJid.of(jid, true);
+		}
+	}
+
 }

src/main/java/eu/siacs/conversations/xmpp/InvalidJid.java

@@ -41,6 +41,7 @@ public class InvalidJid implements Jid {
 	private InvalidJid(String jid) {
 		this.value = jid;
 	}
+
 	public  static Jid of(String jid, boolean fallback) {
 		final int pos = jid.indexOf('/');
 		if (fallback && pos >= 0 && jid.length() >= pos + 1) {