`child-activated` (fired by a pointer click) was bridged to `child.activate()`
so each card's own connect handler (wired on the child's `activate` signal)
would run. But `child.activate()` runs `GtkFlowBoxChild`'s default handler,
which re-emits `child-activated` on the FlowBox — bouncing straight back into
the same closure. Unguarded, that ping-pong recursed forever, overflowing the
stack on every single host-card click or Enter-key activation (confirmed live
via coredump/gdb: 43k+ stack frames of gobject signal emission, and the
`fatal runtime error: stack overflow, aborting` in the crash log).
A re-entrancy flag breaks the cycle after the one real activation. Added a
regression test that wires the identical FlowBox/FlowBoxChild signal cycle
against a real display and asserts it returns instead of recursing — it
reproduces the exact stack overflow against the old code.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
enricobuehler
53c8eefa99