206801 - Alpha channel not correctly displayed in URL bar Icon

Status: RESOLVED DUPLICATE of bug 198293

(Core :: Graphics: ImageLib, defect)

Description

[Zachariah]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4b) Gecko/20030522
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4b) Gecko/20030522

Unfortunately I have to mention the other two browsers for you to see it working
correctly.  I am not sure if this is a problem other than on the windows
platform (XP Pro).  In IE6, if you bookmark a site using a favicon (in this case
which is in the source of the HTML, rather than a file called "favicon.ico" at
the root of the site), or in Opera 7 if you just visit the site, the correct
icon version is shown.  

Whith monitor resolution set to 16 bit or higher color, Windows XP can display
icons with alpha channels.  Mozilla picks this icon version (in icon files which
have multiple icons in them, e.g. 16x16, 32x32 ... and 16 color, 256 color, high
color, and alpha), but then does not render the icon using the alpha channels. 
If Mozilla picks the "XP icon" out of the choices available in the file, then it
should render the alpha channel properly.  Otherwise if Mozilla is not going to
render that alpha channel, then it should pikc a lower resolution version out of
the choices available in the icon file, and display that one (in this case 16x16
at 256 colors).  

I have not tried including 256, high color, and "XP" icons, to see if the
correct icon is chosen.  The example URL contains only 16x16, 32x32, 48x48, and
128x128 at 256 color and "XP" versions (no high-color version).  

Reproducible: Always

Steps to Reproduce:
1. Navigate to www.expandingvision.com in Opera 7 (note icon in address bar)
2. Navigate to www.expandingvision.com in Mozilla (note icon in address bar)
Actual Results:  
Icon displayed incorrectly

Expected Results:  
Either choose the 256 color icon, or display the alpha channel correctly

Comment 1

[Zachariah]

http://www.expandingvision.com/test.shtml
This address shows that the even given the option of high color 16x16, Mozilla
chooses the "XP" version.  The icon for the test page is different than the one at:
http://www.expandingvision.com/
in that it has 3 color resolutions (256, high, and "XP")

Comment 2

[Matthias Versen [:Matti]]

.

Comment 3

[Jim Dunn]

isn't this a dup of bug 198293

Comment 4

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

indeed it is, marking so.

*** This bug has been marked as a duplicate of 198293 ***

Comment 5

[Zachariah]

For the record I did look long and hard to find mention of this bug prior to
submitting it.  Glad to see that someone else could.  I hope it wasn't too
terribly time consuming for anyone.  Sorry