Rollback transactions only when an error occurs.

[nieqiurong]

If the transaction is committed, rollback will be invalid.
It's better to put the transaction rollback operation into the exception block

[coveralls]

coverage: 87.256% (+0.02%) from 87.235%
when pulling e88ddb1 on nieqiurong:20250312130529
into 1a145cd on mybatis:master.

[harawata]

Hello @nieqiurong ,

These tests are passing without the change (there should be a test case that requires the proposed change to pass).

FYI, here is the Javadoc comment of ScriptRunner.

This is an internal testing utility.
You are welcome to use this class for your own purposes,
but if there is some feature/enhancement you need for your own usage,
please make and modify your own copy instead of sending us an enhancement request.

So, unless this fixes an obvious bug, we may reject the PR.
Personally, I really really want to move this class to src/test/.

[nieqiurong]

This is not a defect, it's just a misunderstanding when reading