HHH-18961 JtaIsolationDelegate, obtaining connection : NPE when SQLExceptionConversionDelegate#convert returns null

Author: dreab8

hibernate-core/src/main/java/org/hibernate/resource/transaction/backend/jta/internal/JtaIsolationDelegate.java

@@ -200,7 +200,11 @@ private <T> T doTheWork(WorkExecutorVisitable<T> work) {
 			}
 		}
 		catch (SQLException e) {
-			throw sqlExceptionConverter().apply( e, "unable to obtain isolated JDBC connection" );
+			final JDBCException jdbcException = sqlExceptionConverter().apply( e, "unable to obtain isolated JDBC connection" );
+			if ( jdbcException == null ) {
+				throw new HibernateException( "Unable to obtain isolated JDBC connection", e );
+			}
+			throw jdbcException;
 		}
 	}