https://bugs.kde.org/show_bug.cgi?id=525170
--- Comment #2 from [email protected] --- Created attachment 195747 --> https://bugs.kde.org/attachment.cgi?id=195747&action=edit screen recording I attached screen recording. The most important is that after duplication of text the cursor ends up below visible area. Here's the most important info claude extracted: Here's the proof I pulled from the signal frame (the CPU state at the instant of the fault, before KCrash re-raised): trapno = 14 (page fault), err = 4 → user-mode READ of a non-present page CR2 = 0x0000000000000000 ← the address that was dereferenced = NULL RDI = 0x0000000000000000 ← arg1 'this' (the QTextLine) = NULL RDI is the first argument of QTextLine::xToCursor — i.e. the QTextLine/its engine pointer — and it is null. The faulting read was at address 0. So xToCursor was invoked on a non-existent (null) QTextLine, and it crashed dereferencing null. Thread 1 (Thread 0x79cd058fbdc0 (LWP 95578)): #0 __pthread_kill_implementation (threadid=<optimized out>, signo=11, no_tid=0) at ./nptl/pthread_kill.c:44 tid = <optimized out> ret = 0 pd = <optimized out> old_mask = {__val = {0}} ret = <optimized out> #1 __pthread_kill_internal (threadid=<optimized out>, signo=11) at ./nptl/pthread_kill.c:89 #2 __GI___pthread_kill (threadid=<optimized out>, signo=signo@entry=11) at ./nptl/pthread_kill.c:100 #3 0x000079cd0d645b7e in __GI_raise (sig=11) at ../sysdeps/posix/raise.c:26 ret = <optimized out> #4 0x000079cd0f7dfd8d in KCrash::defaultCrashHandler(int) () at /usr/lib/x86_64-linux-gnu/libKF6Crash.so.6 #5 0x000079cd0d645cb0 in <signal handler called> () at /usr/lib/x86_64-linux-gnu/libc.so.6 #6 0x000079cd0e8dfc82 in QTextLine::xToCursor(double, QTextLine::CursorPosition) const () at /usr/lib/x86_64-linux-gnu/libQt6Gui.so.6 #7 0x000079cd0d3973e8 in ??? () at /usr/lib/x86_64-linux-gnu/libKF6TextEditor.so.6 #8 0x000079cd0d4296a4 in ??? () at /usr/lib/x86_64-linux-gnu/libKF6TextEditor.so.6 #9 0x000079cd0dfea525 in ??? () at /usr/lib/x86_64-linux-gnu/libQt6Core.so.6 #10 0x000079cd0e98f2ea in QAction::triggered(bool) () at /usr/lib/x86_64-linux-gnu/libQt6Gui.so.6 -- You are receiving this mail because: You are watching all bug changes.
