Public bug reported: The problem
I've installed latest LTS Kubuntu 20.04 (Focal Fossa) with all latest updates. When I tried to see pictures on my phone connected via USB via via "mtp" protocol in "Gwenview" application I've found that I can't open all but the first picture in a directory. Precisely: 1. Open in Gwenview application a remote directory via mtp with small previews; 2. Click on the first picture to see it with full size - it works; 3. Click on any other picture to see it with full size - either black rectangular "error loading metadata" info is displayed; 4. Right-click on the picture to open it in Okular or another Gwenview instance - it works. There is no such problem with looking at local directories. Expected behavior - to be able to see all pictures in full size from 'preview' mode in a single instance of Gwenview. Investigation and resolution The bug seems to be fixed in Kubuntu 21.04. And there is no such erroneous behavior while viewing local pictures. Firstly I thought it's a bug in Gwenview and started to debug it. But after debugging I've observed that as long as the application creates more than one KIO::TransferJob objects as many copies of the same chunks of data came via each next transfer object. Thus the only first created transfer object works as expected. That's why I could observe only the first picture in my phone's directory. And this is the reason to believe that Gwenview is not the root cause of the behavior. I've created a trivial console application to get the same file twice from a phone and got the same erroneous behavior. I've taken a look at all commits in upstream source code (https://github.com/KDE/kio-extras) between versions used in 20.04 and 21.04 Kubuntu for mtp module and found that f4e0183adfd8bf4fd6b9f8e7edea6cb35362c206 change looks related to my problem. I've got source code for v19.12.3 tag of kio-extras packages, applied that commit together with 94e7b64325f9e71196a19fb5bc396b9e82f88fc7 and placed resulted mtp.so and kmtpd.so modules in my system. The bug has gone. Versions > lsb_release -rd Description: Ubuntu 20.04.2 LTS Release: 20.04 > LC_ALL=C apt-cache policy kio-extras kio-extras: Installed: 4:19.12.3a-0ubuntu2 Candidate: 4:19.12.3a-0ubuntu2 Version table: *** 4:19.12.3a-0ubuntu2 500 500 http://ru.archive.ubuntu.com/ubuntu focal/universe amd64 Packages 100 /var/lib/dpkg/status > LC_ALL=C apt-cache policy gwenview gwenview: Installed: 4:19.12.3-0ubuntu2 Candidate: 4:19.12.3-0ubuntu2 Version table: *** 4:19.12.3-0ubuntu2 500 500 http://ru.archive.ubuntu.com/ubuntu focal/universe amd64 Packages 100 /var/lib/dpkg/status ** Affects: kio-extras (Ubuntu) Importance: Undecided Status: New ** Attachment added: "a test application source and an output of it" https://bugs.launchpad.net/bugs/1937915/+attachment/5513380/+files/test.tar.bz2 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1937915 Title: kio duplicates data got via mtp module To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/kio-extras/+bug/1937915/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
