Merge branch 'accounting' into dev

accounting/src/main/java/de/srsoftware/umbrella/accounting/SqliteDb.java

@@ -295,7 +295,7 @@ public class SqliteDb extends BaseDb implements AccountDb {
 			}
 		} else if (transaction.isDirty()) {
 			try {
-				if (transaction.amount() == 0) {
+				if (transaction.amount() == 0 || transaction.source().isEmpty() || transaction.destination().isEmpty()) {
 					delete().from(TABLE_TRANSACTIONS).where(Field.ID, equal(transaction.id())).where(ACCOUNT, equal(transaction.accountId())).execute(db);
 				} else {
 					replaceInto(TABLE_TRANSACTIONS, Field.ID, Field.ACCOUNT, Field.TIMESTAMP, Field.SOURCE, Field.DESTINATION, Field.AMOUNT, Field.DESCRIPTION)

core/src/main/java/de/srsoftware/umbrella/core/model/IdOrString.java

@@ -6,6 +6,9 @@ import de.srsoftware.umbrella.core.constants.Field;
 import java.util.HashMap;
 import java.util.Map;
 
+import static de.srsoftware.tools.Optionals.isSet;
+import static de.srsoftware.tools.Optionals.nullIfEmpty;
+
 public class IdOrString implements Mappable {
 		private final Long id;
 		private final String value;
@@ -52,6 +55,10 @@ public class IdOrString implements Mappable {
 			return map;
 		}
 
+	public boolean isEmpty() {
+			return id == null && !isSet(value);
+	}
+
 	@Override
 	public String toString() {
 		return value;