[net] NullpointerException on FTPClient.disconnect() if an Exception occured while FTPClient.connect

• Key: NET-59
• Type: Bug
• Status: Closed
• Resolution: Fixed
• Priority: Major
• Assignee: Unassigned
• Reporter: Christian Hufgard
• Affects Version/s: 1.2
• Fix Version/s: 2.0

Environment

Operating System: All
Platform: Other

Description

Hello,

think this bug is the same (or at least similiar) to the following one:
http://issues.apache.org/bugzilla/show_bug.cgi?id=26296
but since I was not sure, I opened it as a seperate report.

Versions affected: commons-net-1.2.2, think also commons-net-1.4.0

Problem: If an exception occures while FTPClient.connect() is running, a call to
FTPClient.disconnect() in a finally-block might throw a NullPointerException.
I am pretty shure, that this might cause some Threads so keep alive, also they
cannot be interrupted anymore.

Reason: This happens since TelnetClient.disconnect() does not check whether the
Streams (__input and __ouput) it tries to close are NULL or not.
Normally it is sufficent to check FTPClient.isConnected(), but if a exceptions
is thrown after SocketClient._connectAction has been excecuted, SocketClient.
isConnected is set to true, so the check will indicate that the connection is
alive.

Christian