MySQL Bugs: #55340: initializeResultsMetadataFromCache fails on second call to stored proc

Bug #55340	initializeResultsMetadataFromCache fails on second call to stored proc
Submitted:	18 Jul 2010 8:04	Modified:	25 Nov 2013 20:13
Reporter:	Bill Culp	Email Updates:
Status:	Closed	Impact on me:	None
Category:	Connector / J	Severity:	S2 (Serious)
Version:	5.1.13	OS:	MacOS
Assigned to:	Filipe Silva	CPU Architecture:	Any
Tags:	Connector/J

Description:
Caused by: java.lang.NullPointerException
	at com.mysql.jdbc.ConnectionImpl.initializeResultsMetadataFromCache(ConnectionImpl.java:5486)

When enabling cacheResultSetMetadata=true&amp;cacheCallableStmts=true&amp;cachePrepStmts=true

If you call a stored procedure that returns a result set, the second time you call it a null pointer is thrown in the connection impl.

How to repeat:
Enable the properties cacheResultSetMetadata=true&amp;cacheCallableStmts=true&amp;cachePrepStmts=true

Call a stored procedure that returns a result set.  Return the connection to the pool or close.  prepare the statement again with the same sql and call execute().

Caused by: java.lang.NullPointerException
	at com.mysql.jdbc.ConnectionImpl.initializeResultsMetadataFromCache(ConnectionImpl.java:5486)
	at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:1370)
	at com.mysql.jdbc.CallableStatement.execute(CallableStatement.java:879)
	at org.apache.tomcat.dbcp.dbcp.DelegatingPreparedStatement.execute(DelegatingPreparedStatement.java:169)

Suggested fix:
----> LINE 1369 PreparedStatement.java 

		if (cachedMetadata != null) {
				locallyScopedConn.initializeResultsMetadataFromCache(this.originalSql,
						cachedMetadata, this.results);  <---------------- this is wrong
			} else {
				if (rs.reallyResult() && locallyScopedConn.getCacheResultSetMetadata()) {
					locallyScopedConn.initializeResultsMetadataFromCache(this.originalSql,
							null /* will be created */, rs); <---------------- this is right
				}
			}

Make the call pass in rs and not this.results; this.results cant possibly be populated in this logic

Thanks Bill.

Verified on the basis of Mark's analysis. Could be tough to fix though.

Added an entry to the Connector/J 5.1.28 changelog:

"With cacheResultSetMetadata=true, cacheCallableStmts=true, and cachePrepStmts=true, if a stored procedure that returns a result set was called, calling the stored procedure a second time resulted in a null pointer exception being thrown for initializeResultsMetadataFromCache."