[BUG] Slave can't re-sync with master again after changing password

[ChrisZMF]

Describe the bug
If the connection between master and slave is broken (reasons may be network error, restarting master... ) after changing the password of master, the slave can't resynchronize with master again automatically. The resynchronization will fail because slave can't auth master successfully though the masterauth of slave is set rightly. It can be resolved by restarting slave with new masterauth or execute slaveof no one to reset the master-slave relationship.

• OS: all
• Version: all

To Reproduce
Steps to reproduce the behavior:

1. Sync server B(slave) with server A(master)
2. Set or change requirepass of A and masterauth of B at the same time
3. Restart master with new password, then slave can't resync with master.

Expected behavior
The B(slave) can re-sync with A(master) automatically.

Reason Analysis
When slave sync with master, a ReplicationThread object will be created and the password of master will be assigned to its member variable auth_. Although the value of masterauth is re-assigned, auth_ will still hold the old value because it can't be re-assigned dynamically.

[git-hulk]

cool, can you help to handle this issue? @ChrisZMF

[ChrisZMF]

OK, I will fix it soon.