XnView MP Linux
Version 0.88 64bits (Nov 2 2017)
OS: Linux 64bit (Xubuntu 16.04.2 LTS)
After producing JPG files from my RAW images, I use XNViewMP's handy "Change Timestamp" feature to batch process all of them and reset the Modified Date to be their original EXIF Date Taken. This has always worked very well for me. In one of the recent updates though (couldn't swear to it being the latest), this lovely tool has started leaving a temp file, with the extension ".jpg_exiftool_tmp" for every file that it touches. (The filename matches the original jpg's filename.)
Effect: Annoying temp files are created which clutter up the directory, and if the tool is opened again (without first deleting the tmp file) to perform an additional the operation on the file, an error dialog appears and the operation fails.
To reproduce:
1. Select a file with EXIF data
2. Open the Change Timestamp tool
3. Change the file date and click Write
4. Click Cancel (should really say "Close" because we're not cancelling what we just did!)
5. Press F5 to refresh the file list
Actual behaviour (bug): A file is created with the same filename as the original, but with the extension ".jpg_exiftool_tmp"

Expected behaviour: File EXIF data is updated.
This can all be done over again, and if the ".jpg_exiftool_tmp" file is present in the folder, then an error is thrown. (See screenshot.)