SQLException XJ215 on insert with setCharacterStream() and autocommit off in mailjdbc test

I am running the 10.5 maildbc test on Linux with network server and the 10.5.2.0 release candidate and an updated derbyTesting.jar to have just Lily's change to change the backup user: I see in the test output early and often, this error inserting data into the table:

SQLState: XJ215
Severity: 20000
Message: You cannot invoke other java.sql.Clob/java.sql.Blob methods after calling the free() method or after
Clob's transaction has been committed or rolled back.
java.sql.SQLException: You cannot invoke other java.sql.Clob/java.sql.Blob methods after calling the free() m
ter the Blob/Clob's transaction has been committed or rolled back.
at org.apache.derby.client.am.SQLExceptionFactory40.getSQLException(Unknown Source)
at org.apache.derby.client.am.SqlException.getSQLException(Unknown Source)
at org.apache.derby.client.am.Lob.checkValidity(Unknown Source)
at org.apache.derby.client.am.Clob.length(Unknown Source)
at org.apache.derby.client.net.NetStatementRequest.computeProtocolTypesAndLengths(Unknown Source)
at org.apache.derby.client.net.NetStatementRequest.buildSQLDTAcommandData(Unknown Source)
at org.apache.derby.client.net.NetStatementRequest.writeExecute(Unknown Source)
at org.apache.derby.client.net.NetPreparedStatement.writeExecute_(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.writeExecute(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.flowExecute(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.executeUpdateX(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.executeUpdate(Unknown Source)
at org.apache.derbyTesting.system.mailjdbc.utils.DbTasks.insertMail(DbTasks.java:447)
at org.apache.derbyTesting.system.mailjdbc.tasks.Refresh.insertMail(Refresh.java:99)
at org.apache.derbyTesting.system.mailjdbc.tasks.Refresh.doWork(Refresh.java:75)
at org.apache.derbyTesting.system.mailjdbc.tasks.Refresh.run(Refresh.java:51)
Caused by: org.apache.derby.client.am.SqlException: You cannot invoke other java.sql.Clob/java.sql.Blob metho
lling the free() method or after the Blob/Clob's transaction has been committed or rolled back.

The interesting thing is that the test itself is not using any Clob methods it uses setCharacterStream and also autocommit is off.
Below is a code excerpt and
conn.setAutoCommit(false);
PreparedStatement insertFirst = conn.prepareStatement(
Statements.insertStr, Statement.RETURN_GENERATED_KEYS);
String name = new String("ABCD");
String l_name = new String("WXYZ");
long s_insert = System.currentTimeMillis();
for (int i = 0; i < num; i++) {
String new_name = new String(increment(name, 60));
String new_lname = new String(decrement(l_name, 60));
insertFirst.setString(1, new_name);
insertFirst.setString(2, new_lname);
insertFirst.setTimestamp(3, new Timestamp(System
.currentTimeMillis()));
name = new_name;
l_name = new_lname;
try

{ // to create a stream of random length between 200 bytes and 3MB int clobLength = Rn.nextInt(3078000 - 200 + 1) + 200; streamReader = new LoopingAlphabetReader(clobLength, CharAlphabet.modernLatinLowercase()); insertFirst.setCharacterStream(4, streamReader, clobLength); }

catch (Exception e)

{ MailJdbc.logAct.logMsg(LogFile.ERROR + thread_name + " : " + "File not found Exception : " + e.getMessage()); errorPrint(e); throw e; }

int rand_num = Rn.nextInt(10 - 1);
if (i == rand_num) {
ResultSet rs = stmt
.executeQuery("select count from REFRESH.INBOX where attach_id>0");
while (rs.next())

{ id_count = rs.getInt(1); insertFirst.setInt(5, rs.getInt(1) + 1); }

rs.close();
conn.setTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);
} else
insertFirst.setInt(5, 0);
insertFirst
.setString(
6,
"This column is used only to by pass the space problem. If the problem still exists, then we are going to "
+ "have a serious issue here.*****************************************************************************************************");
int result = insertFirst.executeUpdate();

if I connect with ij I do see some rows in the INBOX, so some inserts do seem to be happening.

Kristian pointed out that this looks similar to DERBY-4224 with setAsciiStream() but this looks far more serious as autocommit is off and there does not appear to be a commit, so there is no obvious workaround. I assume this is also a regression. We shouldn't be throwing this error if the user did not use any Clob methods. I will try to narrow down the reproduction and track down where the issue was introduced. Knut said DERBY-4224 goes all the way back to 10.3.1.4 with DERBY-208. I don't know if it is the same case with this one.