eog determines image type from filename

Thank you for your bug report. This bug has already been reported to the developers of the software. You can track it and make comments here: http://bugzilla.gnome.org/show_bug.cgi?id=490067

I've been wanting this too.
It would be nice if the program alerted the user of the incorrect extension for the filename and suggested the automatic rename of it.

By the way, this bug is from 2007.... any news on this?

I'm sure it wouldn't be so hard to change.. it already automatically detects the filetype when you open an image without extension.

Still the same on Natty. When I remember this correctly, the behaviour was another one some versions ago. It would be way better if eog would determite the file type not by the fileextension.

This is a really nasty bug, because there are often images on the web that don't have the correct extension. A user who don't knows about this would possibly delete such files because he thinks the file is corrupted.

Test this with this file:

http://wallbase.net/wallpaper/379454

It's been 5 years and still no sign of this bug being fixed. The eog project looks nearly dead.
feh doesn't have this bug, is more featureful and runs much much faster than eog.
 $ apt-get install feh
 $ mv image.jpg image.gif
 $ feh -dZF image.gif

Yep,
But now ubuntu comes with shotwell in the the box. Shotwell do this in right way too.

True, but if you want to view lots of images with a responsive user-interface, feh is more than 10 times faster than shotwell. If you start shotwell from the command-line with a large number of images as arguments, then type <Space> as fast as you can (or increase your keyboard's default autorepeat rate) to load the next image, shotwell takes about 1/3 second to move to the next image. With feh, it takes about 30 milliseconds.

Scanning old print photos at my local Walgreens results in a CD with PNG files named with a .jpg extension, which triggers this bug.