Dragging "file system" icon even a short distance attempts to copy from / to somewhere

[zahlman]

Distribution

Mint 22.3

Package version

6.6.3

Frequency

Always

Bug description

The special "Computer" folder seems to treat its contained "File System" icon (representing the path /) as if it were just another folder, despite the abstraction it's trying to create. Worse, Nemo doesn't seem to recognize the impossibility of copying or moving / into another folder.

Steps to reproduce

• Double-click "Computer" icon on desktop, or navigate to computer:///
• Press and hold "File System" icon, then begin to drag
• Observe that a green "plus" appears next to the cursor

If the mouse is released on the Desktop, Nemo begins to prepare a large copying operation, presumably of the entire filesystem. (Destination is unclear as I closed the dialog immediately, not wanting to risk any copying.)

If instead the shift key is held, and "File System" released within the "Computer" window, all Nemo windows close, apparently a crash.

Expected behavior

Nemo should never offer or attempt to move or copy /, since there is normally no good reason to attempt it and because there is nowhere sensible it could be copied (without taking care to exclude the destination). This kind of copying should be the responsibility of more specialized tools. Dragging an icon within a window and releasing it within the same window should never have an effect.

More specifically:

• Dragging within the "Computer" window should have no effect; the plus should not appear, whether or not the shift key is pressed, and the window should persist after dropping the icon. In other words, it should behave the same way as for icons representing a storage device or CD drive.

• Attempting to move or copy "File System" onto the Desktop should produce an immediate error dialog, similar to an attempt to move or copy an ordinary folder into itself.

Additional information

The crash is 100% reproducible and produces console output like:

$ nemo --quit && nemo
sys:1: Warning: g_object_ref: assertion 'G_IS_OBJECT (object)' failed
sys:1: Warning: g_object_unref: assertion 'G_IS_OBJECT (object)' failed

(nemo:3307373): GLib-GIO-CRITICAL **: 17:31:49.643: g_file_get_child: assertion '!g_path_is_absolute (name)' failed

(nemo:3307373): GLib-GIO-CRITICAL **: 17:31:49.643: g_file_get_child: assertion '!g_path_is_absolute (name)' failed

(nemo:3307373): GLib-GIO-CRITICAL **: 17:31:49.643: g_file_move: assertion 'G_IS_FILE (destination)' failed
Segmentation fault (core dumped)

[zahlman]

Thanks for an incredibly fast resolution 🙏

Regarding commentary on the commit:

Clipboard operations do work, and are still supported.

It's unclear to me what sort of operations you have in mind?

The reason I discovered this is because I thought it might be possible to put a "File System" icon on the desktop this way and thus get quick access to /. It seems to me that older versions of Nemo used to offer this, but I'm not really set up to check (I might be completely imagining it).

[mtwebster]

The desktop settings are a bit odd - they're not in the normal nemo preferences.

If you right-click the desktop, and select 'Customize', it'll bring up a window where you can adjust the desktop icons themselves. At the bottom of that window there's a Desktop Settings link, and from there you can enable these icons (if you're running Cinnamon, they're also accessible from 'Desktop' in the start menu).

By clipboard operations, I mean you can still 'copy' a file from somewhere, and 'paste into' those items, from the context menu. It probably won't work on every item that shows up in that view due to permissions, but I could see someone wanting to use that to copy files to a USB stick or external drive, possibly.

[zahlman]

Interesting.

Some of the context menu options might be worth a rethink, particularly "Copy To".

What I meant about desktop icons is that I had a memory of "File System" previously appearing in that configurable list of "Desktop Icons". Again, I may have imagined this.