MySQL Bugs: #2670: setBytes on Blob truncates data

Bug #2670	setBytes on Blob truncates data
Submitted:	6 Feb 2004 19:05	Modified:	4 Aug 2004 16:39
Reporter:	joseph dane	Email Updates:
Status:	Closed	Impact on me:	None
Category:	Connector / J	Severity:	S1 (Critical)
Version:	3.0.9	OS:	darwin
Assigned to:	Mark Matthews	CPU Architecture:	Any

Description:
if you have a Blob of a certain length, say 1000 bytes, and you use setBytes() on the blob
to set the values of a subset of the bytes (say the first 10), then the remainder of the blob is 
truncated, and you're left with a 10 byte blob.

there's nothing in the Blob spec to lead be to believe that this is correct.

How to repeat:
roughly, something like this:

   Blob b = rs.getBlob(1);  // 1000 byte blob
   byte[] bytes = new byte[10];
   ...
   b.setBytes(1, bytes, 0, 10);  // the blob is now only 10 bytes long, and the remaining 990 bytes 
are lost 
   

Suggested fix:
as noted in the current Blob source, the implementaion is pretty much "brain dead".  the correct
long term fix will depend on how the "brain transplant" is performed.

for now, I suggest removing the use of the output stream in setBytes(), and just using a 
System.arraycopy, since you've already got the whole blob in memory anyhow.

I have a fix prepared, pending some clarification of the JDBC standard on what to do if the index to write at is greater than the current blob length.

Thank you for your bug report. This issue has already been fixed
in the latest released version of that product, which you can download at 
http://www.mysql.com/downloads/