Minecraft erroneously resizing when using auto-pause toggle

I disable Minecraft's automatic pause using the debug toggle "F3+P" so that it is easier to interact with the client while writing plugins for bukkit. However, I've discovered that there is a flaw with its implementation, most likely due to lack of testing since it is a debug command.

The problem is that with auto-pause off, if the window loses focus, and a resize is attempted on any corner or side, then the window will quickly shrink on its own to a microscopic size. The window can then become "stuck" in this state and require that Minecraft be restarted.

The problem is due to Minecraft incorrectly handling the window-activation event and, while the user is attempting the resize action, Minecraft is at the same time trying to take control of the cursor by pulling it to the center of the window, towards the game crosshair.

The solution to this problem is to tell Minecraft to regain focus only if the user has clicked within the client area instead of just the window.