Issue #28350: String constants with null character no longer interned.

Author: serhiy-storchaka

Lib/test/test_code.py

@@ -135,19 +135,27 @@ def test_newempty(self):
         self.assertEqual(co.co_name, "funcname")
         self.assertEqual(co.co_firstlineno, 15)
 
+
+def isinterned(s):
+    return s is sys.intern(('_' + s + '_')[1:-1])
+
 class CodeConstsTest(unittest.TestCase):
 
     def find_const(self, consts, value):
         for v in consts:
             if v == value:
                 return v
-        self.assertIn(value, consts)  # rises an exception
-        self.fail('Should be never reached')
+        self.assertIn(value, consts)  # raises an exception
+        self.fail('Should never be reached')
 
     def assertIsInterned(self, s):
-        if s is not sys.intern(s):
+        if not isinterned(s):
             self.fail('String %r is not interned' % (s,))
 
+    def assertIsNotInterned(self, s):
+        if isinterned(s):
+            self.fail('String %r is interned' % (s,))
+
     @cpython_only
     def test_interned_string(self):
         co = compile('res = "str_value"', '?', 'exec')
@@ -172,6 +180,12 @@ def f(a='str_value'):
             return a
         self.assertIsInterned(f())
 
+    @cpython_only
+    def test_interned_string_with_null(self):
+        co = compile(r'res = "str\0value!"', '?', 'exec')
+        v = self.find_const(co.co_consts, 'str\0value!')
+        self.assertIsNotInterned(v)
+
 
 class CodeWeakRefTest(unittest.TestCase):
 

Misc/NEWS

@@ -10,6 +10,8 @@ What's New in Python 3.6.0 beta 2
 Core and Builtins
 -----------------
 
+- Issue #28350: String constants with null character no longer interned.
+
 - Issue #26617: Fix crash when GC runs during weakref callbacks.
 
 - Issue #27942: String constants now interned recursively in tuples and frozensets.

Objects/codeobject.c

@@ -19,21 +19,21 @@ static int
 all_name_chars(PyObject *o)
 {
     static char ok_name_char[256];
-    static unsigned char *name_chars = (unsigned char *)NAME_CHARS;
-    PyUnicodeObject *u = (PyUnicodeObject *)o;
-    const unsigned char *s;
+    static const unsigned char *name_chars = (unsigned char *)NAME_CHARS;
+    const unsigned char *s, *e;
 
-    if (!PyUnicode_Check(o) || PyUnicode_READY(u) == -1 ||
-        PyUnicode_MAX_CHAR_VALUE(u) >= 128)
+    if (!PyUnicode_Check(o) || PyUnicode_READY(o) == -1 ||
+        !PyUnicode_IS_ASCII(o))
         return 0;
 
     if (ok_name_char[*name_chars] == 0) {
-        unsigned char *p;
+        const unsigned char *p;
         for (p = name_chars; *p; p++)
             ok_name_char[*p] = 1;
     }
-    s = PyUnicode_1BYTE_DATA(u);
-    while (*s) {
+    s = PyUnicode_1BYTE_DATA(o);
+    e = s + PyUnicode_GET_LENGTH(o);
+    while (s != e) {
         if (ok_name_char[*s++] == 0)
             return 0;
     }