487562 - GIF with larger "Logical screen: Width and Height displays incorrectly

Status: RESOLVED WORKSFORME

(Core :: Graphics: ImageLib, defect)

Description

[Anthony Thyssen]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.8) Gecko/2009032713 Fedora/3.0.8-1.fc10 Firefox/3.0.8
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.8) Gecko/2009032713 Fedora/3.0.8-1.fc10 Firefox/3.0.8

the given "paged.gif" has a 64x64 logical area but only contains a 46x46 frame within the image.  Typically this is used for animations, but in this case it is just a single frame GIF image so does not animate or loop.

however the logical screen to the right of the actral image frame comes out black instead of transparent.

For an example of where this is used (and was created) see  http://www.imagemagick.org/Usage/crop/#crop



Reproducible: Always

Steps to Reproduce:
1. Create image, or use the one given
2.open or display image in firefox
3.look for the black pixels that should be transparent!


Expected Results:  
All browsers (going back to the oldest mosaic!) before this version of firefox display the background (transparency) for the parts not covered by the actual image frame contained by the GIF image.

Comment 1

[Ria Klaassen (not reading all bugmail)]

Is this Linux only? I see nothing unexpected on Windows.

Comment 2

[philippe (part-time)]

Yeah, I see this is with the latest Minefield running on Ubuntu810.
I think this is a dupe though, but haven't found it yet.

Comment 3

[philippe (part-time)]

Attachment: one of the images

Comment 4

[philippe (part-time)]

Attachment: screenshot

Comment 5

[Anthony Thyssen]

My machine is running the latest version available for Fedora 10 Linux.

Comment 6

[Anthony Thyssen]

My firefox on my Fedora 10 linux system was just upgraded to  v3.0.9

The bug however still remains!!!!

GIF images displayed on a larger Logical screen  show black areas to the right of the actual image,  rather than transparency as it should and does show for other areas of the displayed 'logical screen' of the image file format.

Even the Ancient Mosaic broswer handled this aspect of GIFs correctly!

Comment 7

[Anthony Thyssen]

Adddendum...

the problem also effecting GIF animations, but only for the first frame of such an animation.    Fast changing animations will probably not be noticable.

For an example of this see 
   http://www.imagemagick.org/Usage/anim_basics/#background

which is a basic example of a GIF animation only using 'background' disposal.

Another bug report  https://bugzilla.mozilla.org/show_bug.cgi?id=333120 is related to this, BUT missleading as that bug is requesting something that would break accepted practise in GIF animation handling by browsers.

Comment 8

[Anthony Thyssen]

Problems remain in Linux Firefox v3.0.10

They do not appear on Windows IE, for Firefox v2

Comment 9

[Anthony Thyssen]

still present in Firefox Linux v3.0.12

Comment 10

[Anthony Thyssen]

The problem still exists for Firefox Mozilla 3.0.14 for any GIF with a smaller real image on a larger virtual display area.   It also happens for the first (and only the first) frame on an animation, if that animations frame also does not fill out the whole physical display area.

Comment 11

[Anthony Thyssen]

How long does it take to fix what should be a simple bug to squash!

Comment 12

[Anthony Thyssen]

Problem now appears to be fixed with Firefox 3.5.9

Comment 13

[Nickolay_Ponomarev]

Thanks for the report and for the updates. Sorry you didn't get a reply. Please re-open if it's actually not fixed.