Duplication issue has been raised several times on the forum. I’d like to distinguish this post by emphasizing that this bug happens OUTSIDE of initial sync. It’s NOT “filename (2)” kind of duplicate on local computer. And I can reproduce this issue consistently with scripts.
To reproduce this issue:
Have some files in a folder A in Google Drive. Make sure Insync has synced all of them.
Have some other files with the exact same set of filenames, but different content, in an external folder B (not synced with Google Drive)
Move the files in folder A to a newly created folder C also in Google Drive
Move the files in folder B to folder A
Delete folder C and the files in it
Note: step 4 and 5 may be interchanged, but step 3-5 must be done in rapid succession. Folder C could be placed anywhere in Google Drive, but in practice placing it as a subfolder of folder A seems to have a higher success rate of reproducing the issue.
Files in folder A are updated with files originally in folder B
Actual buugy result:
On local computer, everything is still fine. But on the cloud, the original files in folder A may not get deleted nor moved to anywhere else, while files originally in folder B are still added to folder A, resulting in two sets of files with the exact same names. The original files in folder A become “zombies” that are stuck in the cloud and can never be accessed, modified, synced or deleted locally by Insync.
How this was discovered:
I noticed the duplication when I was using FreeFileSync. It uses a similar procedure to update folders it syncs. The procedure acts as a fail-safe file copy that prevents data corruption.
I wrote a Python script to reproduce this issue. It can be found here.
The script would repeat this procedure for a number of times. Not every time is guaranteed to have duplicates for all files, but at least half the times there’d be some more duplicates.
My client and system:
Windows 7 Professional SP1
Google Drive official client is not running