Edit: I'm noticing that under "Other Locations" the devices are using the tooltip "Unmount" for their buttons so maybe the same tooltip should be used too.

gtk_places_view_row_set_is_network() does this

>       gtk_widget_set_tooltip_text (GTK_WIDGET (row->eject_button), is_network ? _("Disconnect") : _("Unmount"));

The problem I see is different but still bad: despite that, and the default Unmount being set in the .ui file to match the default property value - I never see any tooltip on the eject_button, and the Inspector says it's NULL.

IOW, far as I can tell, your problem is caused not because the button has the same tooltip as the row - but because it gets _no_ tooltip, and therefore the one from the row overall (as normally seen when hovering its label) wins out.

Needless to say, this occurs in Nautilus too.

Finally, I'm not certain if it's relevant, but it still seems worth noting explicitly that these strings - both in the .ui and .c files - are marked as translatable.

Created attachment 357982 [details] [review]
SidebarRow: Add Unmount tooltip to eject_button

It was reported that the lack of a tooltip made its purpose unclear.
This can be solved by just copying PlacesViewRow’s eject_button tooltip.

--

I was looking in the wrong widget. PlacesViewRow is for the main area and does
have a tooltip, but SidebarRow does not, hence this bug.

The solution seems obvious to me: make SidebarRow have the same tooltip in the
equivalent place.

This of course does not conditionally show Disconnect for network locations as
PlacesViewRow does, because SidebarRow has no awareness or property for that
(and, honestly, I have no idea whether we can put such locations in the sidebar)

(Personally, I would've preferred Eject, but I presume it makes more sense to copy terminology already used in equivalent situations elsewhere)