[DERBY-4060] Blob.getBinaryStream(long,long) is off by one for the pos+len check

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 10.3.3.1, 10.4.2.0, 10.5.1.1
• Fix Version/s: 10.3.3.1, 10.4.2.1, 10.5.1.1
• Component/s: JDBC, Network Client
• Urgency: Normal
• Assignee: Kristian Waagan
• Reporter: Trejkaz
• Created: 16/Feb/09 22:00
• Updated: 12/May/10 07:39
• Resolved: 09/Mar/09 09:54

Description

If you have a BLOB of length 20, and call blob.getBinaryStream(11,10), it will give you an error:

java.sql.SQLException: Sum of position('11') and length('10') is greater than the size of the LOB.

This is following word for word an error in the JDBC Javadoc:

SQLException - if pos is less than 1 or if pos is greater than the number of bytes in the Blob or if pos + length is greater than the number of bytes in the Blob

So it's checking 11 + 10 > 20, but it should check 11 + 10 > 21 (pos + len > blob.length() + 1) to allow reading the last byte.

The Javadoc for Clob.getCharacterStream(long,long) has similar wording so it may have the same issue.

Likewise, the client driver may have the same issue – I haven't yet checked.