Last night, I discovered this in my code.
memset(msg, 0, MSG_SIZE);
I was debugging this for days. This was for a simple chatting program. The server would take the messages from the clients and distribute them to the other clients.
It would only send the message to the first client. But, if the first client sent the message, the server would send the message to the second client because it would skip the client that send the message.
Also the persistent undo on my Vim stopped working. It may be related to me downloading gVim to enable the system clipboard on my terminal Vim.
pain.