1.6.4: Portrait orientation lost when IPTC data added to NEF and DNG files

[heXnForum]

XnView: MP 1.6.4 - 64 bit Libformat 7.170
OS: Windows 10 64bit

If IPTC information (ctrl+I) is added to a .NEF or .DNG (this was converted from a .NEF using DxO PureRaw) file, where the image has an upright/portrait orientation (EXIF prm Orientation: Rotate 90 CW) the thumbnail of the image is displayed in horizontal orientation, when the folder is accessed NEXT time (EXIF prm is unchanged). If the thumbnails is regenerated via View > Regenerate thumbnails the image becomes upright but is displayed horizontal again with the next access of the folder. The regeneration is not persistent. The orientation of the preview of the image maintains correct.

Effect: Persistent wrong oritentation of thumbnails, which should be upright

To reproduce:
1. Select a portrait orientated .NEF file in folder 1
2. Add some IPTC information via ctrl+I
3. Select folder 2 (any other)
4. Re-select folder 1 > thumbnail is displayed horizontally
5. Select thumbnail again and do View > Regenerate thumbnails > thumbnail is upright
6. Repeat step 2 and 3 > thumbnail is horizontal again

Actual behaviour (bug): portrait thumbnail is turned horizontal instead of maintaining its orientation.

Expected behaviour: thumbnail should maintain its orientation.

Regards, Heimo

N.B. There was a similar bug in the past which I could attribute to the setting of categories. An odd number of categories selected caused the image to flip, if not done in very short time (delayed write). I tried this again but could not associate the bug above with the setting of categories.

[xnview]

please send a sample file?

[heXnForum]

Were you able to download the test images from the link I sent you.

[xnview]

yes, Thanks to your detailed description I can reproduce the problem.

[xnview]

This problem is supposed to be fixed in XnView MP 1.6.5. Please check and confirm the bug fix here.

[heXnForum]

The bug is fixed. Thank you for the quick resolution.