bpo-42393: Raise OverflowError iso. DeprecationWarning on overflow in socket.ntohs and socket.htons (GH-23980)

There was a race condition in base64 in lazy initialization of multiple globals.

Doc/library/socket.rst

@@ -907,11 +907,9 @@ The :mod:`socket` module also offers various network-related services:
    where the host byte order is the same as network byte order, this is a no-op;
    otherwise, it performs a 2-byte swap operation.
 
-   .. deprecated:: 3.7
-      In case *x* does not fit in 16-bit unsigned integer, but does fit in a
-      positive C int, it is silently truncated to 16-bit unsigned integer.
-      This silent truncation feature is deprecated, and will raise an
-      exception in future versions of Python.
+   .. versionchanged:: 3.10
+      Raises :exc:`OverflowError` if *x* does not fit in a 16-bit unsigned
+      integer.
 
 
 .. function:: htonl(x)
@@ -927,11 +925,9 @@ The :mod:`socket` module also offers various network-related services:
    where the host byte order is the same as network byte order, this is a no-op;
    otherwise, it performs a 2-byte swap operation.
 
-   .. deprecated:: 3.7
-      In case *x* does not fit in 16-bit unsigned integer, but does fit in a
-      positive C int, it is silently truncated to 16-bit unsigned integer.
-      This silent truncation feature is deprecated, and will raise an
-      exception in future versions of Python.
+   .. versionchanged:: 3.10
+      Raises :exc:`OverflowError` if *x* does not fit in a 16-bit unsigned
+      integer.
 
 
 .. function:: inet_aton(ip_string)

Doc/whatsnew/3.10.rst

@@ -537,6 +537,12 @@ Changes in the Python API
   silently in Python 3.9.
   (Contributed by Ken Jin in :issue:`42195`.)
 
+* :meth:`socket.htons` and :meth:`socket.ntohs` now raise :exc:`OverflowError`
+  instead of :exc:`DeprecationWarning` if the given parameter will not fit in
+  a 16-bit unsigned integer.
+  (Contributed by Erlend E. Aasland in :issue:`42393`.)
+
+
 CPython bytecode changes
 ========================
 

Lib/base64.py

@@ -344,7 +344,7 @@ def a85encode(b, *, foldspaces=False, wrapcol=0, pad=False, adobe=False):
     global _a85chars, _a85chars2
     # Delay the initialization of tables to not waste memory
     # if the function is never called
-    if _a85chars is None:
+    if _a85chars2 is None:
         _a85chars = [bytes((i,)) for i in range(33, 118)]
         _a85chars2 = [(a + b) for a in _a85chars for b in _a85chars]
 
@@ -452,7 +452,7 @@ def b85encode(b, pad=False):
     global _b85chars, _b85chars2
     # Delay the initialization of tables to not waste memory
     # if the function is never called
-    if _b85chars is None:
+    if _b85chars2 is None:
         _b85chars = [bytes((i,)) for i in _b85alphabet]
         _b85chars2 = [(a + b) for a in _b85chars for b in _b85chars]
     return _85encode(b, _b85chars, _b85chars2, pad)

Lib/test/test_socket.py

@@ -1121,9 +1121,11 @@ class GeneralModuleTests(unittest.TestCase):
         s_good_values = [0, 1, 2, 0xffff]
         l_good_values = s_good_values + [0xffffffff]
         l_bad_values = [-1, -2, 1<<32, 1<<1000]
-        s_bad_values = l_bad_values + [_testcapi.INT_MIN - 1,
-                                       _testcapi.INT_MAX + 1]
-        s_deprecated_values = [1<<16, _testcapi.INT_MAX]
+        s_bad_values = (
+            l_bad_values +
+            [_testcapi.INT_MIN-1, _testcapi.INT_MAX+1] +
+            [1 << 16, _testcapi.INT_MAX]
+        )
         for k in s_good_values:
             socket.ntohs(k)
             socket.htons(k)
@@ -1136,9 +1138,6 @@ class GeneralModuleTests(unittest.TestCase):
         for k in l_bad_values:
             self.assertRaises(OverflowError, socket.ntohl, k)
             self.assertRaises(OverflowError, socket.htonl, k)
-        for k in s_deprecated_values:
-            self.assertWarns(DeprecationWarning, socket.ntohs, k)
-            self.assertWarns(DeprecationWarning, socket.htons, k)
 
     def testGetServBy(self):
         eq = self.assertEqual

Misc/ACKS

@@ -1659,6 +1659,7 @@ Quentin Stafford-Fraser
 Frank Stajano
 Joel Stanley
 Kyle Stanley
+Brandon Stansbury
 Anthony Starks
 David Steele
 Oliver Steele

Misc/NEWS.d/next/Library/2019-12-16-17-55-31.bpo-39068.Ti3f9P.rst

@@ -0,0 +1,2 @@
+Fix initialization race condition in :func:`a85encode` and :func:`b85encode`
+in :mod:`base64`. Patch by Brandon Stansbury.

Misc/NEWS.d/next/Library/2020-11-17-22-06-15.bpo-42393.BB0oXc.rst

@@ -0,0 +1,3 @@
+Raise :exc:`OverflowError` instead of silent truncation in :meth:`socket.ntohs`
+and :meth:`socket.htons`.  Silent truncation was deprecated in Python 3.7.
+Patch by Erlend E. Aasland

Modules/socketmodule.c

@@ -6102,13 +6102,10 @@ socket_ntohs(PyObject *self, PyObject *args)
         return NULL;
     }
     if (x > 0xffff) {
-        if (PyErr_WarnEx(PyExc_DeprecationWarning,
-                         "ntohs: Python int too large to convert to C "
-                         "16-bit unsigned integer (The silent truncation "
-                         "is deprecated)",
-                         1)) {
-            return NULL;
-        }
+        PyErr_SetString(PyExc_OverflowError,
+                        "ntohs: Python int too large to convert to C "
+                        "16-bit unsigned integer");
+        return NULL;
     }
     return PyLong_FromUnsignedLong(ntohs((unsigned short)x));
 }
@@ -6116,12 +6113,7 @@ socket_ntohs(PyObject *self, PyObject *args)
 PyDoc_STRVAR(ntohs_doc,
 "ntohs(integer) -> integer\n\
 \n\
-Convert a 16-bit unsigned integer from network to host byte order.\n\
-Note that in case the received integer does not fit in 16-bit unsigned\n\
-integer, but does fit in a positive C int, it is silently truncated to\n\
-16-bit unsigned integer.\n\
-However, this silent truncation feature is deprecated, and will raise an\n\
-exception in future versions of Python.");
+Convert a 16-bit unsigned integer from network to host byte order.");
 
 
 static PyObject *
@@ -6173,13 +6165,10 @@ socket_htons(PyObject *self, PyObject *args)
         return NULL;
     }
     if (x > 0xffff) {
-        if (PyErr_WarnEx(PyExc_DeprecationWarning,
-                         "htons: Python int too large to convert to C "
-                         "16-bit unsigned integer (The silent truncation "
-                         "is deprecated)",
-                         1)) {
-            return NULL;
-        }
+        PyErr_SetString(PyExc_OverflowError,
+                        "htons: Python int too large to convert to C "
+                        "16-bit unsigned integer");
+        return NULL;
     }
     return PyLong_FromUnsignedLong(htons((unsigned short)x));
 }
@@ -6187,12 +6176,7 @@ socket_htons(PyObject *self, PyObject *args)
 PyDoc_STRVAR(htons_doc,
 "htons(integer) -> integer\n\
 \n\
-Convert a 16-bit unsigned integer from host to network byte order.\n\
-Note that in case the received integer does not fit in 16-bit unsigned\n\
-integer, but does fit in a positive C int, it is silently truncated to\n\
-16-bit unsigned integer.\n\
-However, this silent truncation feature is deprecated, and will raise an\n\
-exception in future versions of Python.");
+Convert a 16-bit unsigned integer from host to network byte order.");
 
 
 static PyObject *