bpo-42562: Fix issue when dis failed to parse function that has no line numbers (GH-23632)

Fix issue when dis failed to parse function that has only annotations

1 files changed, 17 insertions, 0 deletions

diff --git a/Lib/test/test_dis.py b/Lib/test/test_dis.py
index d0743d62e3..56d8771518 100644
--- a/Lib/test/test_dis.py
+++ b/Lib/test/test_dis.py
@@ -166,6 +166,20 @@ dis_bug1333982 = """\
        bug1333982.__code__.co_firstlineno + 2,
        bug1333982.__code__.co_firstlineno + 1)
 
+
+def bug42562():
+    pass
+
+
+# Set line number for 'pass' to None
+bug42562.__code__ = bug42562.__code__.replace(co_linetable=b'\x04\x80\xff\x80')
+
+
+dis_bug42562 = """\
+          0 LOAD_CONST               0 (None)
+          2 RETURN_VALUE
+"""
+
 _BIG_LINENO_FORMAT = """\
 %3d           0 LOAD_GLOBAL              0 (spam)
               2 POP_TOP
@@ -520,6 +534,9 @@ class DisTests(unittest.TestCase):
 
         self.do_disassembly_test(bug1333982, dis_bug1333982)
 
+    def test_bug_42562(self):
+        self.do_disassembly_test(bug42562, dis_bug42562)
+
     def test_big_linenos(self):
         def func(count):
             namespace = {}