"Author Sort" corrupted when using "Download metadata"
Calibre 2.41, Windows 7 64bit
When using the Download metadata feature in the Edit Metadata dialog, the Author Sort field gets changed unexpectedly when no Author data is downloaded.
1. Open the Edit Metadata dialog.
2. Change the Author Sort field to be something other than what is normally derived from the Author field.
3. Configure download metadata to NOT download Authors.
4. Click on Download metadata.
5. Choose one of the found metadata selections.
6. Click Ok to accept.
7. Click Ok to accept the current cover.
The Author Sort field gets updated as if you had clicked on the button to automatically set it from the Author field. If you have already set it automatically, you don't see any visible change. But if you have, it overwrites what you had manually set there.
The Author Sort field should NOT be unexpectedly modified unless the Author field has just been changed when the metadata was downloaded to something different than it was before the operation.
I think causing this update was probably an attempt to streamline the adding of metadata, but when you have configured the metadata downloads to not include authors it is actually ruining any manual settings you have for Author Sort. I noticed this happened unexpectedly and now I am not sure how many of my Author Sorts have been affected by it. I have personally set up the download metadata to only download comments.