bpo-45034: Fix how upper limit is formatted for `struct.pack("H", ...)` (GH-28178)

Co-authored-by: Mark Dickinson <dickinsm@gmail.com>
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/Lib/test/test_struct.py b/Lib/test/test_struct.py
index b3f21ea..49decac 100644
--- a/Lib/test/test_struct.py
+++ b/Lib/test/test_struct.py
@@ -678,6 +678,24 @@ class StructTest(unittest.TestCase):
                                         'embedded null character'):
                 struct.calcsize(s)
 
+    @support.cpython_only
+    def test_issue45034_unsigned(self):
+        from _testcapi import USHRT_MAX
+        error_msg = f'ushort format requires 0 <= number <= {USHRT_MAX}'
+        with self.assertRaisesRegex(struct.error, error_msg):
+            struct.pack('H', 70000)  # too large
+        with self.assertRaisesRegex(struct.error, error_msg):
+            struct.pack('H', -1)  # too small
+
+    @support.cpython_only
+    def test_issue45034_signed(self):
+        from _testcapi import SHRT_MIN, SHRT_MAX
+        error_msg = f'short format requires {SHRT_MIN} <= number <= {SHRT_MAX}'
+        with self.assertRaisesRegex(struct.error, error_msg):
+            struct.pack('h', 70000)  # too large
+        with self.assertRaisesRegex(struct.error, error_msg):
+            struct.pack('h', -70000)  # too small
+
 
 class UnpackIteratorTest(unittest.TestCase):
     """