138476 - Images are not always rendered after "back one page"

Status: RESOLVED DUPLICATE of bug 132549

(Core :: Graphics: ImageLib, defect)

Description

[David W Noon]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (OS/2; U; Warp 4.5; en-US; rv:1.0rc1) Gecko/20020418
BuildID:    2002041811

When I click the "back one page" control to return to a page that has graphics
images, sometimes not all the images are rendered -- even though they were
rendered correctly when the page was first visited.

When I click the "refresh" control the page is then rendered correctly.

Reproducible: Sometimes
Steps to Reproduce:
1. Go to http://news.bbc.co.uk/
2. Select a news article from that page.
3. Click the "back one page" control to return to the BBC home page.
4. See if the any graphics are missing. If so, click "refresh" and they will appear.

Actual Results:  Some screen areas that should have graphics images have the
"missing link" icon instead.

Expected Results:  The page should have been rendered exactly the same as when
it was first visited, only a few seconds earlier.

eComStation 1.0 with SMP, no fixpacks.
Matrox G400 video card, using native OS/2 drivers

Comment 1

[Stephen P. Morse]

reassigning

Comment 2

[Mike Kaply [:mkaply]]

Do you have your disk cache or image cache turned off?

Comment 3

[David W Noon]

I have my disk cache turned off because my machine is connected via a caching
proxy server (Squid) on my LAN's gateway/firewall system.

However, I have set the memory cache to 32 megs, so I don't see why the disk
cache should even be in use. The number and size of the bitmaps involved would
not add up to even 1/8 of the memory cache.

Comment 4

[Mike Kaply [:mkaply]]

Disk cache and memory cache cannot be exchanged one for the other.

Can you try turning disk cache on and seeing if the problem still happens?

Comment 5

[David W Noon]

Reinstating the disk cache seems to have solved the problem.

I still don't understand why disk cache is needed for images. Moreover, if there
is a miss in the cache lookaside, why doesn't the browser simply re-fetch the
image from the original URL? [The caching proxy will supply it very quickly.]

Comment 6

[Mike Kaply [:mkaply]]

*** This bug has been marked as a duplicate of 132549 ***