Bug 510253

SUMMARY
If drag & drop an effect of a clip from one Kdenlive instance to another, the target Kdenlive will segfault.

I found that there are other similar reports (https://bugs.kde.org/show_bug.cgi?id=377581 , https://bugs.kde.org/show_bug.cgi?id=398791) which state that this is currently not implemented.
However, IMO it still shouldn't segfault.

My intention was to copy effects with complex parameters (such as Lift/Gamma/Gain or Curves) from an older project to a newer one. And yes, I'm aware of the library and I very well use it, but in this case I don't know how to do it because I only need the effect and its parameters and not a sequence of a video.

STEPS TO REPRODUCE
1. Open 2 instances of Kdenlive.
2. Add a clip to the timeline of both instances.
3. Add an effect to the clip in the timeline of one of the instances of Kdenlive.
4. Drag & drop this effect to the 2nd instance's timeline clip.

OBSERVED RESULT
Immediate segfault.
`segfault at d8 ip 0000000000b5fe20 sp 00007fffc6e27388 error 4 in kdenlive[75fe20,4d3000+9c6000] likely on CPU 11 (core 11, socket 0)`

EXPECTED RESULT
Effect dropped on the clip.

SOFTWARE/OS VERSIONS
Operating System: Kubuntu 25.04
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.12.0
Qt Version: 6.8.3
Kernel Version: 6.14.0-33-generic (64-bit)

ADDITIONAL INFORMATION
Tested with the current app image 25.08.1 as well as with s a self-compiled version 25.08.2 checkout out from git release/25.08 #0c7bd834ec.