[#CONJ-661] Intermittent NullPointerException in prepareStatement

I believe the fix for this issue is likely similar to these two commits that were made for ~~CONJ-616~~:

We are connecting to an AWS Aurora RDS datasource using a connection string that looks like this:
jdbc:mariadb:aurora://XXXXX.cluster-XXXXX.us-east-1.rds.amazonaws.com:3306/XXXXX?socketTimeout=0&useSSL=true&connectTimeout=31000

After connecting successfully, we are occasionally getting this NullPointerException on calls to prepareStatement:

java.lang.NullPointerException: null

      at org.mariadb.jdbc.internal.failover.impl.MastersSlavesListener.noBackslashEscapes(MastersSlavesListener.java:294)

      at org.mariadb.jdbc.internal.failover.FailoverProxy.invoke(FailoverProxy.java:158)

      at com.sun.proxy.$Proxy18.noBackslashEscapes(Unknown Source)

      at org.mariadb.jdbc.MariaDbConnection.internalPrepareStatement(MariaDbConnection.java:535)

      at org.mariadb.jdbc.MariaDbConnection.prepareStatement(MariaDbConnection.java:350)

      at groovy.sql.Sql$CreatePreparedStatementCommand.execute(Sql.java:4604)

      at groovy.sql.Sql$CreatePreparedStatementCommand.execute(Sql.java:4582)

      at groovy.sql.Sql.getAbstractStatement(Sql.java:4421)

      at groovy.sql.Sql.getPreparedStatement(Sql.java:4436)

      at groovy.sql.Sql.getPreparedStatement(Sql.java:4525)

      at groovy.sql.Sql.eachRow(Sql.java:1282)

      at groovy.sql.Sql.eachRow(Sql.java:1376)

      at groovy.sql.Sql.eachRow(Sql.java:1435)

      at groovy.sql.Sql$eachRow.call(Unknown Source)

In this instance, our input into Groovy's eachRow method was:
sql: "SELECT table_name FROM information_schema.tables where table_schema=current_database() and lower(table_name)=?"
params: ["connection_data"]
closure: irrelevant, we weren't getting far enough into execution for the code to hit this parameter

[CONJ-661] Intermittent NullPointerException in prepareStatement Created: 2018-11-15 Updated: 2020-03-21
Status:	Open
Project:	MariaDB Connector/J
Component/s:	aurora, Failover
Affects Version/s:	2.3.0
Fix Version/s:	None

[CONJ-661] Intermittent NullPointerException in prepareStatement Created: 2018-11-15 Updated: 2020-03-21