Reset monitoring reraise suppression at exception lifecycle boundaries

Clear the existing thread-local suppression flag when a handler receives an exception or an exception escapes a frame, independently of optional monitoring event masks.

Assisted-by: OpenAI Codex:model identifier unavailable

crates/vm/src/frame.rs

@@ -4171,6 +4171,7 @@ impl ExecutingFrame<'_> {
                         Ok(None) => next_idx = lasti_cell.load(Relaxed),
                         Ok(Some(result)) => break Ok(Some(result)),
                         Err(exception) => {
+                            monitoring::reset_reraise_pending();
                             // Fire PY_UNWIND: exception escapes this frame
                             let exception = if vm.state.monitoring_events.load()
                                 & MonitoringEvent::PyUnwind.mask()
@@ -4454,6 +4455,7 @@ impl ExecutingFrame<'_> {
             }
             Ok(Some(result)) => Ok(result),
             Err(exception) => {
+                monitoring::reset_reraise_pending();
                 // Fire PY_UNWIND: exception escapes the generator frame.
                 let exception =
                     if vm.state.monitoring_events.load() & MonitoringEvent::PyUnwind.mask() != 0 {
@@ -8922,6 +8924,7 @@ impl ExecutingFrame<'_> {
                 if let Some(entry) =
                     bytecode::find_exception_handler(&self.code.exceptiontable, offset)
                 {
+                    monitoring::reset_reraise_pending();
                     // Fire EXCEPTION_HANDLED before setting up handler.
                     // If the callback raises, the handler is NOT set up and the
                     // new exception propagates instead.

crates/vm/src/stdlib/sys/monitoring.rs

@@ -1083,6 +1083,12 @@ pub(crate) fn fire_raise(
     )
 }
 
+/// End suppression when the exception reaches a handler or escapes a frame,
+/// independently of whether either lifecycle event has a registered callback.
+pub(crate) fn reset_reraise_pending() {
+    RERAISE_PENDING.with(|f| f.set(false));
+}
+
 /// Only fires if no RERAISE has been fired since the last EXCEPTION_HANDLED,
 /// preventing duplicate events from chained cleanup handlers.
 pub(crate) fn fire_reraise(
@@ -1114,7 +1120,7 @@ pub(crate) fn fire_exception_handled(
     offset: u32,
     exception: &PyObject,
 ) -> PyResult<()> {
-    RERAISE_PENDING.with(|f| f.set(false));
+    reset_reraise_pending();
     fire(
         vm,
         MonitoringEvent::ExceptionHandled,
@@ -1130,7 +1136,7 @@ pub(crate) fn fire_py_unwind(
     offset: u32,
     exception: &PyObject,
 ) -> PyResult<()> {
-    RERAISE_PENDING.with(|f| f.set(false));
+    reset_reraise_pending();
     fire(
         vm,
         MonitoringEvent::PyUnwind,