bpo-46331: Do not set line number of instruction storing doc-string. (GH-30518)

Lib/test/test_sys_settrace.py

@@ -1403,6 +1403,25 @@ class TraceTestCase(unittest.TestCase):
              (3, 'line'),
              (3, 'return')])
 
+    def test_class_creation_with_docstrings(self):
+
+        def func():
+            class Class_1:
+                ''' the docstring. 2'''
+                def __init__(self):
+                    ''' Another docstring. 4'''
+                    self.a = 5
+
+        self.run_and_compare(func,
+            [(0, 'call'),
+             (1, 'line'),
+             (1, 'call'),
+             (1, 'line'),
+             (2, 'line'),
+             (3, 'line'),
+             (3, 'return'),
+             (1, 'return')])
+
 
 class SkipLineEventsTraceTestCase(TraceTestCase):
     """Repeat the trace tests, but with per-line events skipped"""

Misc/NEWS.d/next/Core and Builtins/2022-01-10-16-21-54.bpo-46331.h1AC-i.rst

@@ -0,0 +1,2 @@
+Do not set line number of instruction storing doc-string. Fixes regression
+introduced in 3.11 alpha.

Python/compile.c

@@ -2034,6 +2034,7 @@ compiler_body(struct compiler *c, asdl_stmt_seq *stmts)
             st = (stmt_ty)asdl_seq_GET(stmts, 0);
             assert(st->kind == Expr_kind);
             VISIT(c, expr, st->v.Expr.value);
+            UNSET_LOC(c);
             if (!compiler_nameop(c, __doc__, Store))
                 return 0;
         }