267682 - Getting RSS feeds should send "If-Modified-Since" header

Status: RESOLVED FIXED

(MailNews Core :: Feed Reader, enhancement)

Description

[Hama]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.0; rv:1.7.3) Gecko/20040913 Firefox/0.10.1
Build Identifier: Mozilla Thunderbird 0.9 (Windows/20041103)

Thunderbird downloads all of feeds whether or not it is modified since last
download.
If HTTP request includes "If-Modified-Since" header, the server may return "304
Not Modified" response with no contents.
This can save traffic and time of download.

Reproducible: Always
Steps to Reproduce:

Comment 1

[Scott MacGregor]

Attachment: the fix

1) After downloading a feed, we now look for a "Last-Modified" response header
from the server. If we find one, we remember it as an RDF property on the feed.


2) Before downloading a feed, we look for a stored Last-Modified header in the
data source. If we find one, we set a "If-Modified-Since" request header before
opening the request.

3) Handle Not Modified responsese from the server and show an appropriate
message in the status bar instead of treating it like an error.