commit e682b26a6bc6d3db1a44d82db09d26224e82ccb5
author Sergey Fedoseev <fedoseev.sergey@gmail.com> Mon May 25 19:54:40 2020 +0500
committer GitHub <noreply@github.com> Mon May 25 07:54:40 2020 -0700
tree e680c94323d9a5e31b8f8cefd16710a8243a8078
parent ef16958d17e83723334a51428f410f726d6492a7

bpo-34397: Remove redundant overflow checks in list and tuple implementation. (GH-8757)

Objects/listobject.c

diff --git a/Objects/listobject.c b/Objects/listobject.c
index 37fadca..30d2620 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -261,12 +261,8 @@
         PyErr_BadInternalCall();
         return -1;
     }
-    if (n == PY_SSIZE_T_MAX) {
-        PyErr_SetString(PyExc_OverflowError,
-            "cannot add more objects to list");
-        return -1;
-    }
 
+    assert((size_t)n + 1 < PY_SSIZE_T_MAX);
     if (list_resize(self, n+1) < 0)
         return -1;
 
@@ -301,12 +297,7 @@
     Py_ssize_t n = PyList_GET_SIZE(self);
 
     assert (v != NULL);
-    if (n == PY_SSIZE_T_MAX) {
-        PyErr_SetString(PyExc_OverflowError,
-            "cannot add more objects to list");
-        return -1;
-    }
-
+    assert((size_t)n + 1 < PY_SSIZE_T_MAX);
     if (list_resize(self, n+1) < 0)
         return -1;
 
@@ -503,8 +494,7 @@
         return NULL;
     }
 #define b ((PyListObject *)bb)
-    if (Py_SIZE(a) > PY_SSIZE_T_MAX - Py_SIZE(b))
-        return PyErr_NoMemory();
+    assert((size_t)Py_SIZE(a) + (size_t)Py_SIZE(b) < PY_SSIZE_T_MAX);
     size = Py_SIZE(a) + Py_SIZE(b);
     np = (PyListObject *) list_new_prealloc(size);
     if (np == NULL) {