gh-127572: Fix test_structmembers initialization (GH-127577)

colesbury · web-flow · commit 6fc643674983 · 2024-12-04T09:58:22.000+01:00
gh-127572: Fix `test_structmembers` initialization. The 'C' format code expects an `int` as a destination (not a `char`). This led to test failures on big-endian platforms like s390x. Use the 'c' format code, which expects a `char` as the destination (but requires a Python byte objects instead of a str).
diff --git a/Lib/test/test_capi/test_structmembers.py b/Lib/test/test_capi/test_structmembers.py
@@ -39,7 +39,7 @@ def _make_test_object(cls):
                "hi",   # T_STRING_INPLACE
                12,     # T_LONGLONG
                13,     # T_ULONGLONG
-               "c",    # T_CHAR
+               b"c",   # T_CHAR
                )
 
 
diff --git a/Modules/_testcapi/structmember.c b/Modules/_testcapi/structmember.c
@@ -60,7 +60,7 @@ test_structmembers_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
         "T_FLOAT", "T_DOUBLE", "T_STRING_INPLACE",
         "T_LONGLONG", "T_ULONGLONG", "T_CHAR",
         NULL};
-    static const char fmt[] = "|bbBhHiIlknfds#LKC";
+    static const char fmt[] = "|bbBhHiIlknfds#LKc";
     test_structmembers *ob;
     const char *s = NULL;
     Py_ssize_t string_len = 0;

Original file line number	Diff line number	Diff line change
`@@ -39,7 +39,7 @@ def _make_test_object(cls):`
`39`	`39`	`"hi", # T_STRING_INPLACE`
`40`	`40`	`12, # T_LONGLONG`
`41`	`41`	`13, # T_ULONGLONG`
`42`		`- "c", # T_CHAR`
	`42`	`+ b"c", # T_CHAR`
`43`	`43`	`)`
`44`	`44`
`45`	`45`