Issue #13188: When called without an explicit traceback argument,
generator.throw() now gets the traceback from the passed exception's
`__traceback__` attribute. Patch by Petri Lehtinen.
diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py
index 3ec209b..5f47b3e 100644
--- a/Lib/test/test_generators.py
+++ b/Lib/test/test_generators.py
@@ -1673,6 +1673,32 @@
...
ValueError: 7
+Plain "raise" inside a generator should preserve the traceback (#13188).
+The traceback should have 3 levels:
+- g.throw()
+- f()
+- 1/0
+
+>>> def f():
+... try:
+... yield
+... except:
+... raise
+>>> g = f()
+>>> try:
+... 1/0
+... except ZeroDivisionError as v:
+... try:
+... g.throw(v)
+... except Exception as w:
+... tb = w.__traceback__
+>>> levels = 0
+>>> while tb:
+... levels += 1
+... tb = tb.tb_next
+>>> levels
+3
+
Now let's try closing a generator:
>>> def f():