Incorrect file digest when it is downloaded through webbrowser-app with touch

[Sergio Cazzolato]

I download an image from a webpage and the sha1 digest is not the same than the original. It is happening at least in the krilling (touch).

I tested this scenario with different images and always it is happening the same.

Steps to reproduce:
1. Go to http://lillypilly.canonical.com/~platform-qa/page3.html
2. Touch in the ubuntu image
3. Select Save image
4. Select to open with the Galery
5. Once it is downloaded, press open
6. The file is in ~/Pictures/ubuntu.jpg

The file sha1 digest is 7cad64e34de2eebe73b49756b09a50a4a1948c7a
The original sha1 digest is 429cbd692c4abd3e5c785edf5dcf0993d21076b1

If you download the image either with chrome or firefox, the obtained digest is the correct one.

[Olivier Tilloy (osomon)]

It appears the file saved by UDM under ~/.cache/com.ubuntu.gallery/HubIncoming/ has the expected checksum, but when copied over to ~/Pictures, its checksum changes. A wild guess is that gallery-app modifies the file (maybe the exif metadata).

Note that when saving the same image three times in a row (and renaming the file in between each download), I’m getting three different checksums, which suggests that the contents of the file change in a different way (maybe the exif timestamp?).