python · mdickinson · Sep 7, 2021 · Sep 5, 2021 · Sep 6, 2021 · Sep 6, 2021
diff --git a/Lib/test/test_struct.py b/Lib/test/test_struct.py
@@ -678,6 +678,15 @@ def test_issue35714(self):
                                         'embedded null character'):
                 struct.calcsize(s)
 
+    @support.cpython_only
+    def test_issue45034(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
+
 
 class UnpackIteratorTest(unittest.TestCase):
     """

diff --git a/Misc/NEWS.d/next/Library/2021-09-05-20-33-25.bpo-45034.62NLD5.rst b/Misc/NEWS.d/next/Library/2021-09-05-20-33-25.bpo-45034.62NLD5.rst
@@ -0,0 +1,2 @@
+Changes how max value is formatted for ``struct.pack`` with ``'H'`` mode and
+too large / small numbers.
diff --git a/Modules/_struct.c b/Modules/_struct.c
@@ -607,9 +607,9 @@ np_ushort(_structmodulestate *state, char *p, PyObject *v, const formatdef *f)
     if (get_long(state, v, &x) < 0)
         return -1;
     if (x < 0 || x > USHRT_MAX) {
-        PyErr_SetString(state->StructError,
-                        "ushort format requires 0 <= number <= "
-                        Py_STRINGIFY(USHRT_MAX));
+        PyErr_Format(state->StructError,
+                     "ushort format requires 0 <= number <= %zu",
+                     USHRT_MAX);
         return -1;
     }
     y = (unsigned short)x;
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		Changes how max value is formatted for ``struct.pack`` with ``'H'`` mode and
		too large / small numbers.