bug#15405: 24.3; #[] freezes emacs

[Dmitry Antipov]

On 09/21/2013 01:38 AM, Barry OReilly wrote:

> If performance didn't motivate making a global zero_vector, what did?

1) Small memory saving, like with empty strings.
2) Simple implementation - (eq [] []) is trivial.

BTW, I have no ideas who and why produces empty bytecode strings.
Shouldn't it be disallowed/optimized away? IIUC this is the
only PVEC_xxx type which can be zero-sized.

Dmitry