Bug: I'm not correctly passing through headers

[simonw]

Consider this code:

asgi-csrf/asgi_csrf.py

Lines 63 to 76 in a0647ad

	new_headers = []
	if page_needs_vary_cookie:
	# Loop through original headers, modify or add "vary"
	found_vary = False
	for key, value in original_headers:
	if key == b"vary":
	found_vary = True
	vary_bits = [v.strip() for v in value.split(b",")]
	if b"Cookie" not in vary_bits:
	vary_bits.append(b"Cookie")
	value = b", ".join(vary_bits)
	new_headers.append((key, value))
	if not found_vary:
	new_headers.append((b"vary", b"Cookie"))

If page_needs_vary_cookie is False, the existing headers are not copied over.