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https://issues.apache.org/jira/browse/ZOOKEEPER-3010?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
lujie updated ZOOKEEPER-3010:
-----------------------------
Description:
After ZK-3006 , I develop a very simple static analysis tool to find other
Potential NPE like ZK-3006, this bug is found by this tool and carefully
studied by myself, hopefully someone can confirm it and help me improve this
tool.
h2. Bug description:
callee Learner#findLeader will return null and callee developer check it but
just log:
{code:java}
// code placeholder
if (leaderServer == null) {
LOG.warn("Couldn't find the leader with id = " + current.getId());
}
return leaderServer;
{code}
caller Observer#observeLeader and Follower#followLeader will directly use
return value w/o null check:
{code:java}
//Follower#followLeader
QuorumServer leaderServer = findLeader();
try {
connectToLeader(leaderServer.addr, leaderServer.hostname);
..........
}
//Observer#observeLeader
QuorumServer leaderServer = findLeader();
LOG.info("Observing " + leaderServer.addr);
try {
connectToLeader(leaderServer.addr, leaderServer.hostname);
}{code}
was:
After ZK-3006 , I develop a very simple static analysis tool to find other
Potential NPE like ZK-3006, this bug is found by this tool and carefully
studied by myself, hopefully someone can confirm it.
h2. Bug description:
callee Learner#findLeader will return null and callee developer check it but
just log:
{code:java}
// code placeholder
if (leaderServer == null) {
LOG.warn("Couldn't find the leader with id = " + current.getId());
}
return leaderServer;
{code}
caller Observer#observeLeader and Follower#followLeader will directly use
return value w/o null check:
{code:java}
//Follower#followLeader
QuorumServer leaderServer = findLeader();
try {
connectToLeader(leaderServer.addr, leaderServer.hostname);
..........
}
//Observer#observeLeader
QuorumServer leaderServer = findLeader();
LOG.info("Observing " + leaderServer.addr);
try {
connectToLeader(leaderServer.addr, leaderServer.hostname);
}{code}
> Potential NPE in Observer#observeLeader and Follower#followLeader
> -----------------------------------------------------------------
>
> Key: ZOOKEEPER-3010
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-3010
> Project: ZooKeeper
> Issue Type: Bug
> Affects Versions: 3.6.0
> Environment:
>
> Reporter: lujie
> Priority: Major
>
> After ZK-3006 , I develop a very simple static analysis tool to find other
> Potential NPE like ZK-3006, this bug is found by this tool and carefully
> studied by myself, hopefully someone can confirm it and help me improve this
> tool.
> h2. Bug description:
> callee Learner#findLeader will return null and callee developer check it but
> just log:
> {code:java}
> // code placeholder
> if (leaderServer == null) {
> LOG.warn("Couldn't find the leader with id = " + current.getId());
> }
> return leaderServer;
> {code}
> caller Observer#observeLeader and Follower#followLeader will directly use
> return value w/o null check:
> {code:java}
> //Follower#followLeader
> QuorumServer leaderServer = findLeader();
> try {
> connectToLeader(leaderServer.addr, leaderServer.hostname);
> ..........
> }
> //Observer#observeLeader
> QuorumServer leaderServer = findLeader();
> LOG.info("Observing " + leaderServer.addr);
> try {
> connectToLeader(leaderServer.addr, leaderServer.hostname);
> }{code}
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