Bug 79773 – cached resources are not reused when there are no cache headers present

• Status: ASSIGNED
• Component: Page Loading

[Lea Verou]

Hover over the image in the testcase. You will see that the second image loads again, although it had already been loaded for cross-fade() to work. This is wasteful and should be rectified.

[Radar WebKit Bug Importer]

<rdar://problem/10946032>

[Shezan Baig]

Created attachment 137083 [details]
reduced test case

reduced test case by removing cross-fade (which appears to no longer work in firefox, btw).

We load 2 images, and when mouse hover on the first image, we change it to the second image.  In firefox, this change is instantaneous, but in webkit, this change reloads the image.

the issue has nothing to do with cross-fade itself, but has to do with the fact that cached resources is not reused when there are no cache headers present.  Specifically, CachedResource::freshnessLifetime currently returns 0.  The comment says that other browsers do this, but it seems like firefox doesn't.

I plan to fix this by bumping it up from 0 to 3600 (i.e. 1 hour).  I'm open to alternate suggestions though.

[Simon Fraser (smfr)]

Please re-title this bug to reflect the actual issue.

[Shezan Baig]

Created attachment 137100 [details]
Patch

returning 3600 in freshnessLifetime if no cache headers present

[Alexey Proskuryakov]

Antti should review this.

[Antti Koivisto]

What is the current behavior in other engines? It seems bit risky to change this if everyone else considers these resources uncacheable.

[Antti Koivisto]

Ah you mentioned Firefox. Wonder what their exact behavior is?

[Shezan Baig]

I'm not sure what their exact behavior is, i'll investigate this further

[WebKit Review Bot]

Comment on attachment 137100 [details]
Patch

Attachment 137100 [details] did not pass chromium-ews (chromium-xvfb):
Output: http://queues.webkit.org/results/12405044

New failing tests:
http/tests/misc/script-async.html
http/tests/xmlhttprequest/access-control-basic-allow-preflight-cache.html

[WebKit Review Bot]

Created attachment 137123 [details]
Archive of layout-test-results from ec2-cr-linux-01

The attached test failures were seen while running run-webkit-tests on the chromium-ews.
Bot: ec2-cr-linux-01  Port: <class 'webkitpy.common.config.ports.ChromiumXVFBPort'>  Platform: Linux-2.6.35-28-virtual-x86_64-with-Ubuntu-10.10-maverick

[Ryosuke Niwa]

This is definitely not a CSS bug.

[Alexey Proskuryakov]

Comment on attachment 137100 [details]
Patch

This change needs supportive evidence. Please feel free to ask for review again with evidence provided.