IMAPFolder::close() crashes from time to time when built under MinGW

[paukonen]

Hello!

I built vmime with MinGW and sometimes vmime crashes on this line of IMAPFolder::close():

oldConnection->disconnect();

After some investigation I found out that sometimes (quite rearly) oldConnection happens to be NULL.

I wrapped this code with check and problem dissapeared:

if( oldConnection )
{
// Emit the "CLOSE" command to expunge messages marked
// as deleted (this is fastest than "EXPUNGE")
if (expunge)
{
if (m_mode == MODE_READ_ONLY)
throw exceptions::operation_not_supported();

    IMAPCommand::CLOSE()->send(oldConnection);
}

// Close this folder connection
oldConnection->disconnect();

}

Maybe this problem is specific to MinGW, I didn't checked it with other toolchains.