[OPEN-ILS-DEV] PATCH: osrf_chat.c (memory leaks)

[Scott McKellar]

This patch:

1. Makes sure that all members of OsrfChatServer and OsrfChatNode are
explicitly initialized;

2. Plugs several actual or potential memory leaks.

Commentary:

1. One way to leak memory is to overwrite a non-NULL pointer without
freeing the thing that it pointed to.  However it can be difficult to
determine, by inspecting the code, whether the pointer might have 
been non-NULL in the first place.  

In several cases, rather than try to analyze the entire flow of the
program, I just threw in a test for NULL and freed the pointer if
it wasn't NULL.

It may be that these weren't leaks at all, in which case my additions
will waste a few machine cycles.  At least we can be confident that
we aren't leaking, regardless of how the rest of the program behaves.

2. When destroying an OsrfChatServer, we dutifully free mgr, which
is a pointer to a socket manager.

However a socket_manager owns a linked list of socket_nodes, each of
which owns a socket.  I saw no sign that we were necessarily freeing
all the socket_nodes or closing the sockets.

Were I to analyze the program more carefully, I might determine that
in practice we don't destroy the osrfChatServer until we have already
cleared out the list of socket_nodes.

But I was too lazy to do that.  So I replaced the free() with a call
to socket_manager_free().  At worst I may be wasting a few machine
cycles, but we can be more confident that we are leaking neither
socket_nodes nor sockets.

Scott McKellar
http://home.swbell.net/mck9/ct/

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