212758 - Flash content is never checked for updates until it expires from internal cache (flash driven nagivation)

Status: RESOLVED INCOMPLETE

(Core Graveyard :: Plug-ins, defect)

Description

[Olivier Vit (just a reporter)]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5a) Gecko/20030710
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5a) Gecko/20030710

When Flash content (.swf) is being served without any expiration date, the
internal cache sets an arbitrary expiration date.
Even when setting cache preferences to "Every time I view the page", and when
the load of flash files is driven by other flash files, the browser will never
send requests to the server to check that the orginal content has changed

Reproducible: Always

Steps to Reproduce:
1. setting cache preferences to "Every time I view the page"
2. configure a proxy to monitor http requests
2. go to a web page with flash content and no expiration set in the headers, for
example http://rolexmentorprotege.com/siza/full.html
3. navigate to load another flash file
4. start again from the same url and navigate again
Actual Results:  
no request is issued to check for updated 'child' flash files: obsolete content
can remain displayed to the user if these files have changed since the first
visit and didn't expire from the internal cache


Expected Results:  
send requests and headers like these to check for updates
If-Modified-Since: 
If-None-Match: 
Cache-Control: max-age=0

see also http://bugzilla.mozilla.org/show_bug.cgi?id=163806 about internal cache
odd expiration delays

Comment 1

[Olivier Vit (just a reporter)]

reproduced on w2k build 1.5rc1

Comment 2

[Josh Santangelo]

I can confirm this. With the LiveHTTPHeaders extension, you'll see that the
requests for Flash content never contain the If-Modified-Since header, so the
server always returns 200 instead of 304.

Comment 3

[Olivier Vit (just a reporter)]

the bug summary could be the following: cache setting 'every time I view the
page' isn't honoured for flash content

For example, 
-go to http://www.nissanfrance-promotions.com/micralolitalempicka/index.html
-browse through the different flash modules
- set your proxy settings to a fake proxy server (or, better, watch a trye proxy
log file)
- you are still able to browse through any part of the site built with flash,
you'll get conection errors only when looking on html and static images

=> the plugin relies on the expiration date calculated by the mozilla cache
compenent, and fully ignores the cache user settings to override such expiration
calculation

PS: MSIE 6.0 sends If-Modified-since request in the same situation, while
Mozilla doesn't

Impact: you can NOT rely on Mozilla settings to control Mozilla behavior, you
can hardly use Mozilla when developping and testing a site using Flash content
calling each others since you never know which version of the flash file is
currently loaded

The site being displayed to the user can be very different from what the site
really is...

(tested with 1.7b rc1 on win2k)

Comment 4

[Olivier Vit (just a reporter)]

Still valid in build 2004061507
Will someone consider someday to set it as NEW ??

Comment 5

[ian wood]

I found a stange behaviour with the flash plugin:

a flash XML object loading "filelist.xml" does'nt load a new version of the file
(ala this bug - nothing much new here)

now, if i tell it to load "filelist.php", it does load the new version of
"filelist.xml"... not "filelist.php", which does'nt exist... strange behaviour!
I guess the .php extension tells flash that it needs to query the server, but
the flash XML object looks for filelist.xml anyway?? is it all the flash players
fault??

i thought this may be of interest to anywone working on the bug.

ps: i'm using this mozilla:
Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.7.3) Gecko/20040910
flash player version 7,0,19,0 and swf authored in flash MX 6.00

Comment 6

[ian wood]

an adjunct to the last comment :

when executing myXMLobj.load('filelist.php') for a flash xml object:
if filelist.php exists, it's contents is read (and not from the cache), when it
does'nt exist, filelist.xml is read instead (also not from the cache). 

the problem was that myXMLobj.load('filelist.xml') reads from the cache when
'filelist.xml' has been changed (and mozilla is set to allways check for newer
versions and to have 0MB cache).

hope thats usefull

Comment 7

[bodybuilder]

Attachment: flash menu and animation file

This is still true in the latest firefox version. Everytime I update my flash files on my localhost for testing the new changes will show in IE but not firefox, even when I clear the cache first. the .swf file is called via .js file due to microsofts new security patch that forces users to double click to use flash interactive content. ie. <script src="EmbedHeadertest.js" type="text/javascript"></script>
 
 <script type="text/javascript">RunHeader1();</script>
and the like is the newest method of including flash due to this security patch problem. not sure if it has any effect on how firefox interacts with the cached flash files. but firefox can not be used for developement in this case until all is said and done, then just for cross platform checking.

Comment 8

[Daniel K.]

Still the case in Gran Paradiso Alpha 2.

Comment 9

[Benjamin Smedberg]

If there is still a bug here (and the HTTP cache has been rewritten twice since), we're probably not going to spend engineering time diagnosing or fixing it just for Flash, so I'm going to close this out.