how to trigger "proxy_next_upstream invalid_header"?

[Jeffrey 'jf' Lim]

This is more of a curiosity thing, I guess, than anything else, but...
how do you trigger an "proxy_next_upstream invalid_header" when
testing?

I've tried basically sending random text from an upstream ('nc -l')...
but nginx holds on to the connection and ends up triggering a
"timeout" instead. If I send random text, and then close the
connection, the random text still gets sent to the client, and no next
peer is tried.

-jf

--
He who settles on the idea of the intelligent man as a static entity
only shows himself to be a fool.