LastResourceRecord.shouldAdd allows insertion regardless of order and type info ------------------------------------------------------------------------------- Key: JBTM-1431 URL: https://issues.jboss.org/browse/JBTM-1431 Project: JBoss Transaction Manager Issue Type: Bug Security Level: Public(Everyone can see) Components: Transaction Core Affects Versions: 4.17.3 Reporter: Mark Little Assignee: Mark Little Fix For: 4.17.9, 5.0.0.M2 So looking at the code, LastResource is meant to be ordered last in the intentions list (check topLevelPrepare to see this). However, a quick look at the code in LastResourceRecord shows that there is a bug: public boolean shouldAdd (AbstractRecord a) { if (a.typeIs() == typeIs()) { if (ALLOW_MULTIPLE_LAST_RESOURCES) { if (!_disableMLRWarning || (_disableMLRWarning && !_issuedWarning)) { tsLogger.i18NLogger.warn_lastResource_multipleWarning(a.toString()); _issuedWarning = true; } return true; } else { tsLogger.i18NLogger.warn_lastResource_disallow(this.toString(), a.toString()); return false; } } else { return true; <------- Here is the bug! } } Basically if the record to be added is not a LastResourceRecord then it gets added immediately, ignoring any further checks on type, order etc. This is wrong. And looking back at the code from 6 years ago we see that this was much simpler: public boolean shouldAdd (AbstractRecord a) { return (a.typeIs() == typeIs()) ; }