bpo-44570: Fix line tracing for forwards jumps to duplicated tails (GH-27068)

1 files changed, 35 insertions, 0 deletions

diff --git a/Lib/test/test_sys_settrace.py b/Lib/test/test_sys_settrace.py
index 5f2b908..c42c69d 100644
--- a/Lib/test/test_sys_settrace.py
+++ b/Lib/test/test_sys_settrace.py
@@ -1041,6 +1041,41 @@ class TraceTestCase(unittest.TestCase):
              (-8, 'return'),
              (1, 'return')])
 
+    def test_flow_converges_on_same_line(self):
+
+        def foo(x):
+            if x:
+                try:
+                    1/(x - 1)
+                except ZeroDivisionError:
+                    pass
+            return x
+
+        def func():
+            for i in range(2):
+                foo(i)
+
+        self.run_and_compare(func,
+            [(0, 'call'),
+             (1, 'line'),
+             (2, 'line'),
+             (-8, 'call'),
+             (-7, 'line'),
+             (-2, 'line'),
+             (-2, 'return'),
+             (1, 'line'),
+             (2, 'line'),
+             (-8, 'call'),
+             (-7, 'line'),
+             (-6, 'line'),
+             (-5, 'line'),
+             (-5, 'exception'),
+             (-4, 'line'),
+             (-3, 'line'),
+             (-2, 'line'),
+             (-2, 'return'),
+             (1, 'line'),
+             (1, 'return')])
 
 class SkipLineEventsTraceTestCase(TraceTestCase):
     """Repeat the trace tests, but with per-line events skipped"""