Fix buffer overflow in get_term_size() when using TIOCGWINSZ ioctl

[vlttnv]

Fixes a SystemError: buffer overflow that occurs when the dashboard tries to get the terminal size using fcntl.ioctl() with TIOCGWINSZ.

Problem

The current implementation allocates a 4-byte buffer for the TIOCGWINSZ ioctl call:

raw = fcntl.ioctl(fd, termios.TIOCGWINSZ, ' ' * 4)

However, TIOCGWINSZ returns a complete struct winsize which is 8 bytes, not 4 bytes. According to the man page, the structure contains:

• ws_row (2 bytes) - terminal rows
• ws_col (2 bytes) - terminal columns
• ws_xpixel (2 bytes) - horizontal pixels
• ws_ypixel (2 bytes) - vertical pixels

When the ioctl attempts to write 8 bytes into a 4-byte buffer, Python raises a buffer overflow error.

Solution

Changed the buffer size from 4 bytes to 8 bytes to accommodate the full struct winsize:

raw = fcntl.ioctl(fd, termios.TIOCGWINSZ, ' ' * 8)

The code still only unpacks the first two shorts (height and width) as intended, but now provides adequate buffer space for the entire structure.

Also, we catch SystemError in the except block to fallback to the hardcoded values.

[cyrus-and]

Great catch, thanks! Although a crash never occurred to me...

Polished a bit.