(Please reset version to 2.9.x once bugzilla supports it).

The patches applied in bug 343867 have added proper Exif orientation tag support to gthumb (starting with 2.9.0).

Unfortunately, earlier versions of gthumb had incorrect support. In particular, photos could be imported and "physically" rotated without resetting the orientation tag to "top left" (the default). This didn't matter in earlier versions (unless you were sharing with other applications) because the gthumb display code ignored the orientation tag - i.e., two wrongs made a right.

However, with 2.9.0 and later, users will correctly display the incorrectly-rotated photos. A tool (in the Tools menu) is needed to reset Exif orientation tags in bulk to "top left" to fix this.

For simplicity, I think we need only support reset to "top left", rather than supplying all 8 possible orientation values. (In the future, I hope that gthumb will support general Exif tag editing, for more specialized tweaking - see bug 343021, as well as bug 316666, bug 326101, bug 339648).

If anyone wishes to volunteer to code this, please shout!

I'll take a look at it in a week or two, time permitting, if no one else does.

- Mike