Slowness when browsing MTP folder in list view

Version information

Reproduced with 4.20.2 on Arch Linux and the latest code from master (f2485943)

Steps to reproduce

1. In Thunar's preferences:
   • Uncheck "Remember view settings for each folder"
   • Select "List View" in the View Settings dropdown
2. Close Thunar
3. Attach an MTP device to your computer and mount it
4. Open the root folder of the device (mine is "SanDisk SD card")
   • It takes about 50 seconds to open my "SanDisk SD card" folder, even though it only has 17 folders inside
5. Select View > Compact View
   • It takes about 1 second to refresh the view
6. Select View > List View
   • It takes 20 seconds to refresh the view

Current behavior

The list view is noticeably slower to load than compact view and icon view

Expected outcome

Comparable performance between list view, compact view, and icon view

Additional information

I verified that the same slowness did not occur with 4.18.11 (opening the root folder only took a few seconds).

I will try to profile the code soon to provide more info.

Related package versions:

• gvfs 1.57.2-2
• gvfs-mtp 1.57.2-2
• libmtp 1.1.22-1
• libusb 1.0.28-1