bpo-42645: Make sure that return/break/continue are only traced once when exiting via a finally block. (GH-23780)

* Make sure that return/break/continue are only traced once when exiting via a finally block.

* Add test for return in try-finally.

* Update importlib

1 files changed, 113 insertions, 0 deletions

diff --git a/Lib/test/test_sys_settrace.py b/Lib/test/test_sys_settrace.py
index a842139..3bfc993 100644
--- a/Lib/test/test_sys_settrace.py
+++ b/Lib/test/test_sys_settrace.py
@@ -678,6 +678,119 @@ class TraceTestCase(unittest.TestCase):
              (4, 'line'),
              (4, 'return')])
 
+    def test_if_break(self):
+
+        def func():
+            seq = [1, 0]
+            while seq:
+                n = seq.pop()
+                if n:
+                    break   # line 5
+            else:
+                n = 99
+            return n        # line 8
+
+        self.run_and_compare(func,
+            [(0, 'call'),
+             (1, 'line'),
+             (2, 'line'),
+             (3, 'line'),
+             (4, 'line'),
+             (2, 'line'),
+             (3, 'line'),
+             (4, 'line'),
+             (5, 'line'),
+             (8, 'line'),
+             (8, 'return')])
+
+    def test_break_through_finally(self):
+
+        def func():
+            a, c, d, i = 1, 1, 1, 99
+            try:
+                for i in range(3):
+                    try:
+                        a = 5
+                        if i > 0:
+                            break                   # line 7
+                        a = 8
+                    finally:
+                        c = 10
+            except:
+                d = 12                              # line 12
+            assert a == 5 and c == 10 and d == 1    # line 13
+
+        self.run_and_compare(func,
+            [(0, 'call'),
+             (1, 'line'),
+             (2, 'line'),
+             (3, 'line'),
+             (4, 'line'),
+             (5, 'line'),
+             (6, 'line'),
+             (8, 'line'),
+             (10, 'line'),
+             (3, 'line'),
+             (4, 'line'),
+             (5, 'line'),
+             (6, 'line'),
+             (7, 'line'),
+             (10, 'line'),
+             (13, 'line'),
+             (13, 'return')])
+
+    def test_continue_through_finally(self):
+
+        def func():
+            a, b, c, d, i = 1, 1, 1, 1, 99
+            try:
+                for i in range(2):
+                    try:
+                        a = 5
+                        if i > 0:
+                            continue                # line 7
+                        b = 8
+                    finally:
+                        c = 10
+            except:
+                d = 12                              # line 12
+            assert (a, b, c, d) == (5, 8, 10, 1)    # line 13
+
+        self.run_and_compare(func,
+            [(0, 'call'),
+             (1, 'line'),
+             (2, 'line'),
+             (3, 'line'),
+             (4, 'line'),
+             (5, 'line'),
+             (6, 'line'),
+             (8, 'line'),
+             (10, 'line'),
+             (3, 'line'),
+             (4, 'line'),
+             (5, 'line'),
+             (6, 'line'),
+             (7, 'line'),
+             (10, 'line'),
+             (3, 'line'),
+             (13, 'line'),
+             (13, 'return')])
+
+    def test_return_through_finally(self):
+
+        def func():
+            try:
+                return 2
+            finally:
+                4
+
+        self.run_and_compare(func,
+            [(0, 'call'),
+             (1, 'line'),
+             (2, 'line'),
+             (4, 'line'),
+             (4, 'return')])
+
 
 class SkipLineEventsTraceTestCase(TraceTestCase):
     """Repeat the trace tests, but with per-line events skipped"""