gh-67565: Remove redundant C-contiguity checks (GH-105521)

Co-authored-by: Stefan Krah <skrah@bytereef.org>

1 files changed, 6 insertions, 11 deletions

diff --git a/Python/getargs.c b/Python/getargs.c
index 80d2540a694..5a12ca8def7 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -1187,17 +1187,15 @@ convertsimple(PyObject *arg, const char **p_format, va_list *p_va, int flags,
                 arg, msgbuf, bufsize);
         format++;
 
-        /* Caller is interested in Py_buffer, and the object
-           supports it directly. */
+        /* Caller is interested in Py_buffer, and the object supports it
+           directly. The request implicitly asks for PyBUF_SIMPLE, so the
+           result is C-contiguous with format 'B'. */
         if (PyObject_GetBuffer(arg, (Py_buffer*)p, PyBUF_WRITABLE) < 0) {
             PyErr_Clear();
             return converterr("read-write bytes-like object",
                               arg, msgbuf, bufsize);
         }
-        if (!PyBuffer_IsContiguous((Py_buffer*)p, 'C')) {
-            PyBuffer_Release((Py_buffer*)p);
-            return converterr("contiguous buffer", arg, msgbuf, bufsize);
-        }
+        assert(PyBuffer_IsContiguous((Py_buffer *)p, 'C'));
         if (addcleanup(p, freelist, cleanup_buffer)) {
             return converterr(
                 "(cleanup problem)",
@@ -1242,15 +1240,12 @@ convertbuffer(PyObject *arg, const void **p, const char **errmsg)
 static int
 getbuffer(PyObject *arg, Py_buffer *view, const char **errmsg)
 {
+    /* PyBUF_SIMPLE implies C-contiguous */
     if (PyObject_GetBuffer(arg, view, PyBUF_SIMPLE) != 0) {
         *errmsg = "bytes-like object";
         return -1;
     }
-    if (!PyBuffer_IsContiguous(view, 'C')) {
-        PyBuffer_Release(view);
-        *errmsg = "contiguous buffer";
-        return -1;
-    }
+    assert(PyBuffer_IsContiguous(view, 'C'));
     return 0;
 }