286082 - PDF file with Cache-Control / Expires header not being cached due to Range header

Status: RESOLVED INCOMPLETE

(Core :: Networking: Cache, defect, P3)

Description

[pellentesque]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b2) Gecko/20050313 Firefox/1.0+
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b2) Gecko/20050313 Firefox/1.0+

The PDF file http://www.britishcitizen.info/StatelessReductionProvisions.pdf is
served with a Cache-Control HTTP header and an Expires HTTP header that
instructs the browser (or caching proxy) to store the file for 30 days (see
headers below):

%curl -I http://www.britishcitizen.info/StatelessReductionProvisions.pdf
HTTP/1.1 200 OK
Date: Mon, 14 Mar 2005 11:27:07 GMT
Server: Apache/1.3.29
Cache-Control: max-age=2592000
Expires: Wed, 13 Apr 2005 11:27:07 GMT
Last-Modified: Mon, 14 Mar 2005 09:16:18 GMT
ETag: "289937-bb9a-42355662"
Accept-Ranges: bytes
Content-Length: 48026
Content-Type: application/pdf

However, Firefox does not appear to be caching this PDF at all. When loaded, if
you click back and then click the link to it again, it will re-download the PDF.
After going into about:cache?device=disk and looking for the entry, I found that
there wasn't one. I tried to reproduce this bug with a new profile, and found
the same behaviour: it wasn't being cached and there was no entry for the PDF in
about:cache

Internet Explorer 6 appears to be caching the file correctly. After checking its
cache properties, it correctly set the expiry date to 30 days from initial
download, and loads the file from cache every time without a new download.

On the same server there is a GIF image at
http://www.britishcitizen.info/somerights20.gif which is served with similar
Cache-Control / Expires headers. Firefox seems to handle this one perfectly well.

If it makes a difference, I'm using Adobe Reader 7.0.0.

Reproducible: Always

Steps to Reproduce:
See above
Actual Results:  
It doesn't cache the PDF

Expected Results:  
It should cache the PDF

Comment 1

[Ali Ebrahim]

I've been able to verify the same behaviour as the reporter on both Firefox and
Seamonkey builds from 20050313. I also tried Seamonkey 1.8b1, where the file was
cached correctly, so I'm marking this as a regression.

But at the same time, there was a difference between how 1.8b1 handled it the
file and how trunk Firefox and Seamonkey handle it now. 1.8b1 prompted me to
open or save the file, whereas recent trunk builds just used the Adobe plugin to
display the PDF in the browser. I'm not sure why the change, because both
Seamonkey builds were using the same profile. Maybe this is responsible for the
change in caching behaviour.

In any case, I think the current behaviour is wrong, as the file should clearly
be cached according to the HTTP headers (IE does it fine and does not redownload
the file over and over, even when using the Adobe plugin). I'm leaving this as
unconfirmed for now so that someone else who knows more about this than I do can
make the call, and also moving the bug over to Core since it affects both
Firefox and Seamonkey.

Comment 2

[Ali Ebrahim]

Moving to Networking: Cache (where I wanted it in the first place, but Bugzilla
was trying to be too smart).

Comment 3

[Ali Ebrahim]

Attachment: HTTP log showing download and redownload of said PDF

After clearing the cache, I created an HTTP log of the following steps:

1. Load http://www.britishcitizen.info/
2. Click link to
http://www.britishcitizen.info/StatelessReductionProvisions.pdf (It loads in
the Adobe Reader plugin).
3. Press Back.
4. Click link to
http://www.britishcitizen.info/StatelessReductionProvisions.pdf (It loads in
the Adobe Reader plugin, but redownloads instead of loading from cache, where
it appears not to have been saved).

Comment 4

[Christian :Biesinger (don't email me, ping me on IRC)]

OK...

From the log...
0[274540]: nsHttpChannel::SetRequestHeader [this=1fad6f8 header="Range"
value="bytes=6942-48025,6942-6943" merge=0]
(via
http://lxr.mozilla.org/seamonkey/source/modules/plugin/base/src/nsPluginHostImpl.cpp#1435
I presume. maybe someone should verify that with a debugger or printf)


http://lxr.mozilla.org/seamonkey/source/netwerk/protocol/http/src/nsHttpChannel.cpp#1177
1178         // we don't support caching for byte range requests initiated
1179         // by our clients or via nsIResumableChannel.

so I assume that's what causing this to not use the cache.

Comment 5

[Gervase Markham [:gerv]]

This is an automated message, with ID "auto-resolve01".

This bug has had no comments for a long time. Statistically, we have found that
bug reports that have not been confirmed by a second user after three months are
highly unlikely to be the source of a fix to the code.

While your input is very important to us, our resources are limited and so we
are asking for your help in focussing our efforts. If you can still reproduce
this problem in the latest version of the product (see below for how to obtain a
copy) or, for feature requests, if it's not present in the latest version and
you still believe we should implement it, please visit the URL of this bug
(given at the top of this mail) and add a comment to that effect, giving more
reproduction information if you have it.

If it is not a problem any longer, you need take no action. If this bug is not
changed in any way in the next two weeks, it will be automatically resolved.
Thank you for your help in this matter.

The latest beta releases can be obtained from:
Firefox:     http://www.mozilla.org/projects/firefox/
Thunderbird: http://www.mozilla.org/products/thunderbird/releases/1.5beta1.html
Seamonkey:   http://www.mozilla.org/projects/seamonkey/

Comment 6

[Darin Fisher]

The problem here is that the Adobe PDF plugin is making byte range requests. 
Our cache does not know how to serve byte range requests, so the requests end up
going out over the network.  Here's the tell-tail snipet from the HTTP log file:

0[274540]: nsHttpChannel::SetRequestHeader [this=1fad6f8 header="Range"
value="bytes=6942-48025,6942-6943" merge=0]

Confirming bug.

Comment 7

[Darin Fisher]

-> default owner

Comment 10

[Michelle Funches - QA]

This bug has been tagged for Regression and or Closure.
We have had changes to functionality for PDF "Reader View"
Is this still an issue? If yes please provide updated link to the PDF/Fx Version/OS.
Tested PDF functionality in latest release
Version 	46.0.1
Build ID 	20160502172042
User Agent 	Mozilla/5.0 (Windows NT 5.1; rv:46.0) Gecko/20100101 Firefox/46.0

Comment 11

[Michelle Funches - QA]

Closing as Incomplete:
Feel free to reopen the bug if the issue still reproduces on a current build.
Please provide detailed Steps, Operating System and Firefox version.

Comment 12

[Patrick McManus [:mcmanus]]

michelle - what basis do you have to think this is fixed?

if you'd like to test with the reader and see if it still issues range requests that would be a contribution to the bug..

Comment 13

[Michelle Funches - QA]

Our triage instructions were to close if there is no response after 2 weeks vs a month, as it can be reopened if needed. 
Testing under Comment 10 I saw no issues
Tested: 
The links in this bug have had changes but there in info that I can work with; 
Also tested: http://www.dbsparks.com/research/html/SNRN02.pdf
I do see info in about:cache for these sites
Version 	47.0
Build ID 	20160604131506
User Agent 	Mozilla/5.0 (Windows NT 10.0; WOW64; rv:47.0) Gecko/20100101 Firefox/47.0

Comment 14

[Firefox Bug Husbandry Bot]

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258

Comment 15

[Firefox Bug Husbandry Bot]

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258

Comment 16

[BugBot [:suhaib / :marco/ :calixte]]

A needinfo is requested from the reporter, however, the reporter is inactive on Bugzilla. Closing the bug as incomplete.

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