From 0271cd9db9bb2d9fef01162b956ab6219342377a Mon Sep 17 00:00:00 2001
From: Michael Marshall <mmarshall@apache.org>
Date: Tue, 31 Jan 2023 13:31:08 -0600
Subject: [PATCH] [fix][proxy] Only go to connecting state once (#19331)

Relates to: https://github.com/apache/pulsar/pull/17831#discussion_r1080836860

### Motivation

When the `ProxyConnection` handles a `Connect` command, that is the time to go to `Connecting` state. There is no other time that makes sense to switch to connecting. The current logic will go to connecting in certain re-authentication scenarios, but those are incorrect. By moving the state change to earlier in the logic, we make the state transition clearer and prevent corrupted state.

### Modifications

* Remove `state = State.Connecting` from the `doAuthentication` method, which is called multiple times for various reasons
* Add `state = State.Connecting` to the start of the `handleConnect` method.

### Verifying this change

The existing tests will verify this change, and reading through the code makes it clear this is a correct change.

### Does this pull request potentially affect one of the following parts:

Not a breaking change.

### Documentation

- [x] `doc-not-needed`

It would be nice to map out the state transitions for our connection classes. That is our of the scope of this small improvement.

### Matching PR in forked repository

PR in forked repository: https://github.com/michaeljmarshall/pulsar/pull/21

(cherry picked from commit c8650cef83f558d3942b4c2f5e23c7d0df9eed40)
---
 .../java/org/apache/pulsar/proxy/server/ProxyConnection.java    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pulsar-proxy/src/main/java/org/apache/pulsar/proxy/server/ProxyConnection.java b/pulsar-proxy/src/main/java/org/apache/pulsar/proxy/server/ProxyConnection.java
index 30d36446ccd0e..57ea60e9f1944 100644
--- a/pulsar-proxy/src/main/java/org/apache/pulsar/proxy/server/ProxyConnection.java
+++ b/pulsar-proxy/src/main/java/org/apache/pulsar/proxy/server/ProxyConnection.java
@@ -440,12 +440,12 @@ private void doAuthentication(AuthData clientData)
             LOG.debug("[{}] Authentication in progress client by method {}.",
                     remoteAddress, authMethod);
         }
-        state = State.Connecting;
     }
 
     @Override
     protected void handleConnect(CommandConnect connect) {
         checkArgument(state == State.Init);
+        state = State.Connecting;
         this.setRemoteEndpointProtocolVersion(connect.getProtocolVersion());
         this.hasProxyToBrokerUrl = connect.hasProxyToBrokerUrl();
         this.protocolVersionToAdvertise = getProtocolVersionToAdvertise(connect);