Crash when observer is on the spaceship

[alex-w]

Expected Behaviour

No crash

Actual Behaviour

Crash when observer is on the spaceship in Qt5-based builds

Steps to reproduce

1. Open Stellarium
2. Select planet
3. Press Ctrl+G (flight to the selected planet)
4. Crash

Notes

I can reproduce the issue on macOS/Windows in any Qt5-based builds when RTS data is shower, but not in Qt6-based builds. The issue was introduced in commit 3364be7

In crash dump I see:

Thread 0 Crashed::  Dispatch queue: com.apple.main-thread
0   stellarium                    	       0x104bd3f3c InfoPanel::setTextFromObjects(QList<QSharedPointerNoDelete<StelObject> > const&) + 244
1   stellarium                    	       0x104bd3f2c InfoPanel::setTextFromObjects(QList<QSharedPointerNoDelete<StelObject> > const&) + 228
2   stellarium                    	       0x104bd1390 StelGui::update() + 5236

and no issues in the log.txt

[gzotti]

Hmm. Qt6 debug build. RTS computed for the moon. Select Jupiter, Ctrl-G. Crash with QList::at index out of range, pointing to somewhere in qlist.h, L423. Not really helpful...