fix ctypes test alignment assumptions (closes #20946)

Patch by Andreas Schwab.

2 files changed, 9 insertions, 9 deletions

diff --git a/Lib/ctypes/test/test_bitfields.py b/Lib/ctypes/test/test_bitfields.py
index c89ee34..77de606 100644
--- a/Lib/ctypes/test/test_bitfields.py
+++ b/Lib/ctypes/test/test_bitfields.py
@@ -207,7 +207,7 @@ class BitFieldTest(unittest.TestCase):
         class X(Structure):
             _fields_ = [("a", c_byte, 4),
                         ("b", c_int, 32)]
-        self.assertEqual(sizeof(X), sizeof(c_int)*2)
+        self.assertEqual(sizeof(X), alignment(c_int)+sizeof(c_int))
 
     def test_mixed_3(self):
         class X(Structure):
diff --git a/Lib/ctypes/test/test_structures.py b/Lib/ctypes/test/test_structures.py
index 61b9fe7..87613ad 100644
--- a/Lib/ctypes/test/test_structures.py
+++ b/Lib/ctypes/test/test_structures.py
@@ -83,7 +83,7 @@ class StructureTestCase(unittest.TestCase):
         class Y(Structure):
             _fields_ = [("x", c_char * 3),
                         ("y", c_int)]
-        self.assertEqual(alignment(Y), calcsize("i"))
+        self.assertEqual(alignment(Y), alignment(c_int))
         self.assertEqual(sizeof(Y), calcsize("3si"))
 
         class SI(Structure):
@@ -175,23 +175,23 @@ class StructureTestCase(unittest.TestCase):
         self.assertEqual(sizeof(X), 10)
         self.assertEqual(X.b.offset, 2)
 
+        import struct
+        longlong_size = struct.calcsize("q")
+        longlong_align = struct.calcsize("bq") - longlong_size
+
         class X(Structure):
             _fields_ = [("a", c_byte),
                         ("b", c_longlong)]
             _pack_ = 4
-        self.assertEqual(sizeof(X), 12)
-        self.assertEqual(X.b.offset, 4)
-
-        import struct
-        longlong_size = struct.calcsize("q")
-        longlong_align = struct.calcsize("bq") - longlong_size
+        self.assertEqual(sizeof(X), min(4, longlong_align) + longlong_size)
+        self.assertEqual(X.b.offset, min(4, longlong_align))
 
         class X(Structure):
             _fields_ = [("a", c_byte),
                         ("b", c_longlong)]
             _pack_ = 8
 
-        self.assertEqual(sizeof(X), longlong_align + longlong_size)
+        self.assertEqual(sizeof(X), min(8, longlong_align) + longlong_size)
         self.assertEqual(X.b.offset, min(8, longlong_align))