Created attachment 176715 [details]
kwrite crash backtrace

SUMMARY

Kate and Kwrite are crashing after using search/replace with "escape sequences" and replacing newlines. 

STEPS TO REPRODUCE
1. Open Kwrite
2. Hold down enter until you have like 200 lines
    (About two times the height of the screen in the scroll bar for me)
3. Press CTRL+R to open Replace widget
4. Set it to "Escape Sequences"
5. Search for "\n" and replace with "\t"

OBSERVED RESULT
It renders the replaced text and triggers a segmentation fault.

EXPECTED RESULT
It should just search and replace as it used to do back in the days and not crash afterwards.

SOFTWARE/OS VERSIONS
Operating System: NixOS 25.05
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.8.0
Qt Version: 6.8.0
Kernel Version: 6.12.2-zen1 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 1700X Eight-Core Processor
Memory: 31.3 GiB of RAM
Graphics Processor: NVIDIA GeForce GTX 1060 6GB/PCIe/SSE2

ADDITIONAL INFORMATION
Backtrace attached