757306 - Image loading "progressively" for some reason

Status: NEW

(Core :: Graphics: ImageLib, defect)

Description

[Boris Zbarsky [:bzbarsky]]

See image in the url field.  It visibly loads slowly, even after we should have it cached.  I don't understand why.

See http://stackoverflow.com/questions/10608542/visible-image-buildup-from-top-to-bottom-is-there-a-way-to-show-in-one-stroke for the original thread about this.

Comment 1

[Justin Lebar (not reading bugmail)]

Attachment: The image in question

Comment 2

[Justin Lebar (not reading bugmail)]

Interesting...  Same behavior in chrome on my Linux box.

Loading off bugzilla's servers is better, but I still see a flash as it loads, and I still see a full network request, in Firefox and Chrome.

  data:text/html,<img src="https://bugzilla.mozilla.org/attachment.cgi?id=625882">

Doesn't look like anything is being cached, with either URL, in either browser.  I'd think that caching was being disabled in the HTTP headers, but sabine-schneider.silbe.org is sending back basically zero headers, so that shouldn't disable our cache.

Comment 3

[Boris Zbarsky [:bzbarsky]]

It's not just that.

If you look at the original context for this discussion, there is a copy of this image loaded into one <img> tag and then another <img> tag with the same URI is created.  That should just hit the imagelib cache, I'd think.  And in that situation Chrome's behavior _is_ apparently different.

Comment 4

[Justin Lebar (not reading bugmail)]

Attachment: A second test image

http://en.wikipedia.org/wiki/File:PNG_transparency_demonstration_1.png

Comment 5

[Justin Lebar (not reading bugmail)]

Attachment: Test page