Copy operation may fail if destination is symlink which resides on readonly mount
This is because
G_FILE_ATTRIBUTE_FILESYSTEM_READONLY is used in some cases to check whether we can paste something into a folder, which is wrong. Filesystem attributes give you information about filesystem where the concrete folder resides but doesn't say anything about its descendants. This is a problem when the folder is a symlink from read-only mount to some writable location.
G_FILE_ATTRIBUTE_ACCESS_CAN_WRITE can be used instead in this case if needed.
This behavior was probably changed by commit glib@0f5017fb recently, but I think it is right as it is now.
It affects Copy&Paste context entries and Ctrl+C&Ctrl+V shortcuts but works as expected using drag&drop.
This was initially reported for Thunar on glib#1689 (closed). I can reproduce with
nautilus-3.30.5-1.fc29.x86_64 using the configuration based on NFS mounts described on that issue (over VM provided by reporter privately). I have tried to make a simpler configuration using read-only bind mount, but I can't reproduce with Nautilus in that case, only using Thunar...