drag&drop of files randomly silently fails

[Teo]

I'm not sure whether this is Nautilus or Unity at fault. This happens with both a Nautilus window and the Desktop:

1. In a Nautilus window: click on a file icon, drag it and drop it over a folder. Or hold the Ctrl key and click and drag and drop the file immediately in almost the same place where it was.

In the first case (dragging over a folder) the file should be moved; in the second case the file should be copied. In both cases, if you do it quickly enough, the action is completely ignored and nothing happens.

It seems to be related to the fact that the Launcher (or whatever it is called) shows up on the left of the screen when you start dragging. If its show-up animation is not complete when you drop the item, the drag&drop operation is ignored.

2. On the desktop, the same happens. Or if you simply move an icon (in which case the expected behavior would be for the icon to snap to the nearest position in the grid and stay there) you can also observe that the action is ignored and the icon goes back to its original position.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: unity 5.14.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-27.43-generic 3.2.21
Uname: Linux 3.2.0-27-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu11
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,decor,vpswitch,mousepoll,compiztoolbox,snap,place,resize,session,regex,grid,wall,move,gnomecompat,imgpng,animation,fade,unitymtgrabhandles,workarounds,scale,expo,ezoom,unityshell]
Date: Thu Jul 26 12:44:14 2012
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
ProcEnviron:
 TERM=xterm
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: unity
UpgradeStatus: Upgraded to precise on 2012-05-17 (69 days ago)

[Teo (teo1978)]

This doesn't only happen if done too quickly, this fails randomly about 50% of the times. Even if you wait for the left launcher animation to be completely done before you drop (which I now _always_ do), the drop still silently fails at random times.
Usually, when you redo it a second time it works. But there are times when I retry again and again and it keeps failing, until I deselect, reselect the files and try again and it works.

This is tremendously annoying and it's been already more than 6 months.
It's also DANGEROUS: if you don't realise the copy has not been done, you may delete the original files thinking you have already copied them. Importance should be raised.

[Will Cooke (willcooke)]

As part of the bug clear up ahead of 16.04 we are trying to focus on the bugs which have the largest effect on user experience. Please can you help us by testing to see if this still happening on newer releases? Please try on 15.04.

[teo1978 (teo8976)]

Yes, I have just tested on 15.04 and I still observe the issue, or at least this part:

> 2. On the desktop [...] if you simply move an icon (in which case the expected
> behavior would be for the icon to snap to the nearest position in the grid
> and stay there) you can also observe that the action is ignored and the icon
> goes back to its original position.

As in the original report, it happens randomly, and maybe not as often as I seem to remember it used to.

One note that may (perhaps) help in triaging the issue:
- I now have the Launcher always visible on the left (as opposed to auto-hide/show)
- When I observe the issue (i.e. I drag and drop a file on the desktop and it does not move to the destination position), I observe that the Launcher sort of "flashes" at the very moment I drop the file and it isn't moved (more precisely, icons that are not possible destinations for the dragged file in the Launcher get greyed out for a fraction of a second)
- When I do *not* observe the issue, EITHER I've done it so quickly that the Launcher didn't have time to change its status, OR it did completely, and application icons that are not candidates for accepting the drop have been greyed out for a while.

In my few tests I've just done, I have observed this coincidence all the times; however it may have been random.

[teo1978 (teo8976)]

By the way, I'd like to know whether you tried yourself and couldn't observe the issue, or didn't even try. Would you mind telling me? It's just a curiosity I have about how bugs are handled.

[Will Cooke (willcooke)]

I tried on 14.04 and I can't reproduce.

[teo1978 (teo8976)]

I have also noticed that this does not only happen when dragging and dropping among and within Nautilus windows and/or the Desktop, but also when dragging a file to an application capable of handling it, such as dropping a file into Filezilla (on the server-side panel, i.e. the right one) for upload. In that case, also, at random times the operation is silently ignored.

I would say it does appear to be more likely to happen when the drag-n-drop is done quickly, but it's difficult to say, because most of the times I do it quickly, unless I am re-doing it just after a failure.