emit aboutToRemoveAllFiles causes owncloudcmd to hang wo/ prompt

[SamuAlfageme]

I was just hit by this after discovery:

07-05 12:24:44:910 [ info sync.networkjob.lscol ]:	LSCOL of QUrl("https://<acct>@<server>/remote.php/webdav/<path>/abc") FINISHED WITH STATUS "OK"
07-05 12:24:44:911 [ info sync.discovery ]:	Processing "abc/abc" | valid: true/true/false | mtime: 1625479485/1625479485/0 | size: 0/0/0 | etag: "28b7e:1625479485.077"//"" | checksum: ""//"" | perm: 0x8b1058//0x7f1cb9635998 | fileid: "ZW9zaG9tZS1pMDE6MTY2Nzgy"//"" | inode: 3301694746119/3301694746119/ | type: CSyncEnums::ItemTypeDirectory/CSyncEnums::ItemTypeDirectory/CSyncEnums::ItemTypeFile
07-05 12:24:44:911 [ info sync.discovery ]:	Discovered "abc/abc" CSyncEnums::CSYNC_INSTRUCTION_REMOVE OCC::SyncFileItem::Down CSyncEnums::ItemTypeDirectory
07-05 12:24:44:914 [ info sync.discovery ]:	STARTING "abc/abc" OCC::ProcessDirectoryJob::ParentDontExist "abc/abc" OCC::ProcessDirectoryJob::NormalQuery
07-05 12:24:44:922 [ info sync.engine ]:	#### Discovery end ####################################################  150 ms
07-05 12:24:44:924 [ info sync.engine ]:	All the files are going to be changed, asking the user

client/src/libsync/syncengine.cpp

Line 754 in 9117275

emit aboutToRemoveAllFiles(side >= 0 ? SyncFileItem::Down : SyncFileItem::Up, callback);

... the command line client indefinitely hangs when this condition is met.

[michaelstingl]

@SamuAlfageme run with --non-interactive as a workaround?
(https://doc.owncloud.com/desktop/advanced_usage/command_line_client.html)

[TheOneRing]

Its not handled

[TheOneRing]

Fixed in #8805