#9200: The str.is* methods now work with strings that contain non-BMP characters even in narrow Unicode builds.

3 files changed, 220 insertions, 42 deletions

diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py
index 09cf48f..2858c89 100644
--- a/Lib/test/test_unicode.py
+++ b/Lib/test/test_unicode.py
@@ -345,26 +345,69 @@ class UnicodeTest(string_tests.CommonTest,
     def test_islower(self):
         string_tests.MixinStrUnicodeUserStringTest.test_islower(self)
         self.checkequalnofix(False, '\u1FFc', 'islower')
+        # non-BMP, uppercase
+        self.assertFalse('\U00010401'.islower())
+        self.assertFalse('\U00010427'.islower())
+        # non-BMP, lowercase
+        self.assertTrue('\U00010429'.islower())
+        self.assertTrue('\U0001044E'.islower())
+        # non-BMP, non-cased
+        self.assertFalse('\U0001F40D'.islower())
+        self.assertFalse('\U0001F46F'.islower())
 
     def test_isupper(self):
         string_tests.MixinStrUnicodeUserStringTest.test_isupper(self)
         if not sys.platform.startswith('java'):
             self.checkequalnofix(False, '\u1FFc', 'isupper')
+        # non-BMP, uppercase
+        self.assertTrue('\U00010401'.isupper())
+        self.assertTrue('\U00010427'.isupper())
+        # non-BMP, lowercase
+        self.assertFalse('\U00010429'.isupper())
+        self.assertFalse('\U0001044E'.isupper())
+        # non-BMP, non-cased
+        self.assertFalse('\U0001F40D'.isupper())
+        self.assertFalse('\U0001F46F'.isupper())
 
     def test_istitle(self):
-        string_tests.MixinStrUnicodeUserStringTest.test_title(self)
+        string_tests.MixinStrUnicodeUserStringTest.test_istitle(self)
         self.checkequalnofix(True, '\u1FFc', 'istitle')
         self.checkequalnofix(True, 'Greek \u1FFcitlecases ...', 'istitle')
 
+        # non-BMP, uppercase + lowercase
+        self.assertTrue('\U00010401\U00010429'.istitle())
+        self.assertTrue('\U00010427\U0001044E'.istitle())
+        # apparently there are no titlecased (Lt) non-BMP chars in Unicode 6
+        for ch in ['\U00010429', '\U0001044E', '\U0001F40D', '\U0001F46F']:
+            self.assertFalse(ch.istitle(), '{!a} is not title'.format(ch))
+
     def test_isspace(self):
         string_tests.MixinStrUnicodeUserStringTest.test_isspace(self)
         self.checkequalnofix(True, '\u2000', 'isspace')
         self.checkequalnofix(True, '\u200a', 'isspace')
         self.checkequalnofix(False, '\u2014', 'isspace')
+        # apparently there are no non-BMP spaces chars in Unicode 6
+        for ch in ['\U00010401', '\U00010427', '\U00010429', '\U0001044E',
+                   '\U0001F40D', '\U0001F46F']:
+            self.assertFalse(ch.isspace(), '{!a} is not space.'.format(ch))
+
+    def test_isalnum(self):
+        string_tests.MixinStrUnicodeUserStringTest.test_isalnum(self)
+        for ch in ['\U00010401', '\U00010427', '\U00010429', '\U0001044E',
+                   '\U0001D7F6', '\U00011066', '\U000104A0', '\U0001F107']:
+            self.assertTrue(ch.isalnum(), '{!a} is alnum.'.format(ch))
 
     def test_isalpha(self):
         string_tests.MixinStrUnicodeUserStringTest.test_isalpha(self)
         self.checkequalnofix(True, '\u1FFc', 'isalpha')
+        # non-BMP, cased
+        self.assertTrue('\U00010401'.isalpha())
+        self.assertTrue('\U00010427'.isalpha())
+        self.assertTrue('\U00010429'.isalpha())
+        self.assertTrue('\U0001044E'.isalpha())
+        # non-BMP, non-cased
+        self.assertFalse('\U0001F40D'.isalpha())
+        self.assertFalse('\U0001F46F'.isalpha())
 
     def test_isdecimal(self):
         self.checkequalnofix(False, '', 'isdecimal')
@@ -378,12 +421,24 @@ class UnicodeTest(string_tests.CommonTest,
 
         self.checkraises(TypeError, 'abc', 'isdecimal', 42)
 
+        for ch in ['\U00010401', '\U00010427', '\U00010429', '\U0001044E',
+                   '\U0001F40D', '\U0001F46F', '\U00011065', '\U0001F107']:
+            self.assertFalse(ch.isdecimal(), '{!a} is not decimal.'.format(ch))
+        for ch in ['\U0001D7F6', '\U00011066', '\U000104A0']:
+            self.assertTrue(ch.isdecimal(), '{!a} is decimal.'.format(ch))
+
     def test_isdigit(self):
         string_tests.MixinStrUnicodeUserStringTest.test_isdigit(self)
         self.checkequalnofix(True, '\u2460', 'isdigit')
         self.checkequalnofix(False, '\xbc', 'isdigit')
         self.checkequalnofix(True, '\u0660', 'isdigit')
 
+        for ch in ['\U00010401', '\U00010427', '\U00010429', '\U0001044E',
+                   '\U0001F40D', '\U0001F46F', '\U00011065']:
+            self.assertFalse(ch.isdigit(), '{!a} is not a digit.'.format(ch))
+        for ch in ['\U0001D7F6', '\U00011066', '\U000104A0', '\U0001F107']:
+            self.assertTrue(ch.isdigit(), '{!a} is a digit.'.format(ch))
+
     def test_isnumeric(self):
         self.checkequalnofix(False, '', 'isnumeric')
         self.checkequalnofix(False, 'a', 'isnumeric')
@@ -396,6 +451,13 @@ class UnicodeTest(string_tests.CommonTest,
 
         self.assertRaises(TypeError, "abc".isnumeric, 42)
 
+        for ch in ['\U00010401', '\U00010427', '\U00010429', '\U0001044E',
+                   '\U0001F40D', '\U0001F46F']:
+            self.assertFalse(ch.isnumeric(), '{!a} is not numeric.'.format(ch))
+        for ch in ['\U00011065', '\U0001D7F6', '\U00011066',
+                   '\U000104A0', '\U0001F107']:
+            self.assertTrue(ch.isnumeric(), '{!a} is numeric.'.format(ch))
+
     def test_isidentifier(self):
         self.assertTrue("a".isidentifier())
         self.assertTrue("Z".isidentifier())
@@ -423,6 +485,100 @@ class UnicodeTest(string_tests.CommonTest,
         # single surrogate character
         self.assertFalse("\ud800".isprintable())
 
+        self.assertTrue('\U0001F46F'.isprintable())
+        self.assertFalse('\U000E0020'.isprintable())
+
+    def test_surrogates(self):
+        for s in ('a\uD800b\uDFFF', 'a\uDFFFb\uD800',
+                  'a\uD800b\uDFFFa', 'a\uDFFFb\uD800a'):
+            self.assertTrue(s.islower())
+            self.assertFalse(s.isupper())
+            self.assertFalse(s.istitle())
+        for s in ('A\uD800B\uDFFF', 'A\uDFFFB\uD800',
+                  'A\uD800B\uDFFFA', 'A\uDFFFB\uD800A'):
+            self.assertFalse(s.islower())
+            self.assertTrue(s.isupper())
+            self.assertTrue(s.istitle())
+
+        for meth_name in ('islower', 'isupper', 'istitle'):
+            meth = getattr(str, meth_name)
+            for s in ('\uD800', '\uDFFF', '\uD800\uD800', '\uDFFF\uDFFF'):
+                self.assertFalse(meth(s), '%a.%s() is False' % (s, meth_name))
+
+        for meth_name in ('isalpha', 'isalnum', 'isdigit', 'isspace',
+                          'isdecimal', 'isnumeric',
+                          'isidentifier', 'isprintable'):
+            meth = getattr(str, meth_name)
+            for s in ('\uD800', '\uDFFF', '\uD800\uD800', '\uDFFF\uDFFF',
+                      'a\uD800b\uDFFF', 'a\uDFFFb\uD800',
+                      'a\uD800b\uDFFFa', 'a\uDFFFb\uD800a'):
+                self.assertFalse(meth(s), '%a.%s() is False' % (s, meth_name))
+
+
+    @unittest.skipIf(sys.maxunicode == 65535, 'test requires wide build')
+    def test_lower(self):
+        string_tests.CommonTest.test_lower(self)
+        self.assertEqual('\U00010427'.lower(), '\U0001044F')
+        self.assertEqual('\U00010427\U00010427'.lower(),
+                        '\U0001044F\U0001044F')
+        self.assertEqual('\U00010427\U0001044F'.lower(),
+                        '\U0001044F\U0001044F')
+        self.assertEqual('X\U00010427x\U0001044F'.lower(),
+                        'x\U0001044Fx\U0001044F')
+
+    @unittest.skipIf(sys.maxunicode == 65535, 'test requires wide build')
+    def test_upper(self):
+        string_tests.CommonTest.test_upper(self)
+        self.assertEqual('\U0001044F'.upper(), '\U00010427')
+        self.assertEqual('\U0001044F\U0001044F'.upper(),
+                        '\U00010427\U00010427')
+        self.assertEqual('\U00010427\U0001044F'.upper(),
+                        '\U00010427\U00010427')
+        self.assertEqual('X\U00010427x\U0001044F'.upper(),
+                        'X\U00010427X\U00010427')
+
+    @unittest.skipIf(sys.maxunicode == 65535, 'test requires wide build')
+    def test_capitalize(self):
+        string_tests.CommonTest.test_capitalize(self)
+        self.assertEqual('\U0001044F'.capitalize(), '\U00010427')
+        self.assertEqual('\U0001044F\U0001044F'.capitalize(),
+                        '\U00010427\U0001044F')
+        self.assertEqual('\U00010427\U0001044F'.capitalize(),
+                        '\U00010427\U0001044F')
+        self.assertEqual('\U0001044F\U00010427'.capitalize(),
+                        '\U00010427\U0001044F')
+        self.assertEqual('X\U00010427x\U0001044F'.capitalize(),
+                        'X\U0001044Fx\U0001044F')
+
+    @unittest.skipIf(sys.maxunicode == 65535, 'test requires wide build')
+    def test_title(self):
+        string_tests.MixinStrUnicodeUserStringTest.test_title(self)
+        self.assertEqual('\U0001044F'.title(), '\U00010427')
+        self.assertEqual('\U0001044F\U0001044F'.title(),
+                        '\U00010427\U0001044F')
+        self.assertEqual('\U0001044F\U0001044F \U0001044F\U0001044F'.title(),
+                        '\U00010427\U0001044F \U00010427\U0001044F')
+        self.assertEqual('\U00010427\U0001044F \U00010427\U0001044F'.title(),
+                        '\U00010427\U0001044F \U00010427\U0001044F')
+        self.assertEqual('\U0001044F\U00010427 \U0001044F\U00010427'.title(),
+                        '\U00010427\U0001044F \U00010427\U0001044F')
+        self.assertEqual('X\U00010427x\U0001044F X\U00010427x\U0001044F'.title(),
+                        'X\U0001044Fx\U0001044F X\U0001044Fx\U0001044F')
+
+    @unittest.skipIf(sys.maxunicode == 65535, 'test requires wide build')
+    def test_swapcase(self):
+        string_tests.CommonTest.test_swapcase(self)
+        self.assertEqual('\U0001044F'.swapcase(), '\U00010427')
+        self.assertEqual('\U00010427'.swapcase(), '\U0001044F')
+        self.assertEqual('\U0001044F\U0001044F'.swapcase(),
+                        '\U00010427\U00010427')
+        self.assertEqual('\U00010427\U0001044F'.swapcase(),
+                        '\U0001044F\U00010427')
+        self.assertEqual('\U0001044F\U00010427'.swapcase(),
+                        '\U00010427\U0001044F')
+        self.assertEqual('X\U00010427x\U0001044F'.swapcase(),
+                        'x\U0001044FX\U00010427')
+
     def test_contains(self):
         # Testing Unicode contains method
         self.assertIn('a', 'abdb')
diff --git a/Misc/NEWS b/Misc/NEWS
index da0e67f..6673d20 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@ What's New in Python 3.2.3?
 Core and Builtins
 -----------------
 
+- Issue #9200: The str.is* methods now work with strings that contain non-BMP
+  characters even in narrow Unicode builds.
+
 - Issue #12791: Break reference cycles early when a generator exits with
   an exception.
 
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 77f8dd5..8567a9f 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -6442,6 +6442,37 @@ int PyUnicode_EncodeDecimal(Py_UNICODE *s,
             start = 0;                          \
     }
 
+/* _Py_UNICODE_NEXT is a private macro used to retrieve the character pointed
+ * by 'ptr', possibly combining surrogate pairs on narrow builds.
+ * 'ptr' and 'end' must be Py_UNICODE*, with 'ptr' pointing at the character
+ * that should be returned and 'end' pointing to the end of the buffer.
+ * ('end' is used on narrow builds to detect a lone surrogate at the
+ * end of the buffer that should be returned unchanged.)
+ * The ptr and end arguments should be side-effect free and ptr must an lvalue.
+ * The type of the returned char is always Py_UCS4.
+ *
+ * Note: the macro advances ptr to next char, so it might have side-effects
+ *       (especially if used with other macros).
+ */
+
+/* helper macros used by _Py_UNICODE_NEXT */
+#define _Py_UNICODE_IS_HIGH_SURROGATE(ch) (0xD800 <= ch && ch <= 0xDBFF)
+#define _Py_UNICODE_IS_LOW_SURROGATE(ch) (0xDC00 <= ch && ch <= 0xDFFF)
+/* Join two surrogate characters and return a single Py_UCS4 value. */
+#define _Py_UNICODE_JOIN_SURROGATES(high, low)  \
+    (((((Py_UCS4)(high) & 0x03FF) << 10) |      \
+      ((Py_UCS4)(low) & 0x03FF)) + 0x10000)
+
+#ifdef Py_UNICODE_WIDE
+#define _Py_UNICODE_NEXT(ptr, end) *(ptr)++
+#else
+#define _Py_UNICODE_NEXT(ptr, end)                                      \
+     (((_Py_UNICODE_IS_HIGH_SURROGATE(*(ptr)) && (ptr) < (end)) &&      \
+        _Py_UNICODE_IS_LOW_SURROGATE((ptr)[1])) ?                       \
+       ((ptr) += 2,_Py_UNICODE_JOIN_SURROGATES((ptr)[-2], (ptr)[-1])) : \
+       (Py_UCS4)*(ptr)++)
+#endif
+
 Py_ssize_t PyUnicode_Count(PyObject *str,
                            PyObject *substr,
                            Py_ssize_t start,
@@ -7705,8 +7736,8 @@ unicode_islower(PyUnicodeObject *self)
 
     e = p + PyUnicode_GET_SIZE(self);
     cased = 0;
-    for (; p < e; p++) {
-        register const Py_UNICODE ch = *p;
+    while (p < e) {
+        const Py_UCS4 ch = _Py_UNICODE_NEXT(p, e);
 
         if (Py_UNICODE_ISUPPER(ch) || Py_UNICODE_ISTITLE(ch))
             return PyBool_FromLong(0);
@@ -7739,8 +7770,8 @@ unicode_isupper(PyUnicodeObject *self)
 
     e = p + PyUnicode_GET_SIZE(self);
     cased = 0;
-    for (; p < e; p++) {
-        register const Py_UNICODE ch = *p;
+    while (p < e) {
+        const Py_UCS4 ch = _Py_UNICODE_NEXT(p, e);
 
         if (Py_UNICODE_ISLOWER(ch) || Py_UNICODE_ISTITLE(ch))
             return PyBool_FromLong(0);
@@ -7777,8 +7808,8 @@ unicode_istitle(PyUnicodeObject *self)
     e = p + PyUnicode_GET_SIZE(self);
     cased = 0;
     previous_is_cased = 0;
-    for (; p < e; p++) {
-        register const Py_UNICODE ch = *p;
+    while (p < e) {
+        const Py_UCS4 ch = _Py_UNICODE_NEXT(p, e);
 
         if (Py_UNICODE_ISUPPER(ch) || Py_UNICODE_ISTITLE(ch)) {
             if (previous_is_cased)
@@ -7820,8 +7851,9 @@ unicode_isspace(PyUnicodeObject *self)
         return PyBool_FromLong(0);
 
     e = p + PyUnicode_GET_SIZE(self);
-    for (; p < e; p++) {
-        if (!Py_UNICODE_ISSPACE(*p))
+    while (p < e) {
+        const Py_UCS4 ch = _Py_UNICODE_NEXT(p, e);
+        if (!Py_UNICODE_ISSPACE(ch))
             return PyBool_FromLong(0);
     }
     return PyBool_FromLong(1);
@@ -7849,8 +7881,8 @@ unicode_isalpha(PyUnicodeObject *self)
         return PyBool_FromLong(0);
 
     e = p + PyUnicode_GET_SIZE(self);
-    for (; p < e; p++) {
-        if (!Py_UNICODE_ISALPHA(*p))
+    while (p < e) {
+        if (!Py_UNICODE_ISALPHA(_Py_UNICODE_NEXT(p, e)))
             return PyBool_FromLong(0);
     }
     return PyBool_FromLong(1);
@@ -7878,8 +7910,9 @@ unicode_isalnum(PyUnicodeObject *self)
         return PyBool_FromLong(0);
 
     e = p + PyUnicode_GET_SIZE(self);
-    for (; p < e; p++) {
-        if (!Py_UNICODE_ISALNUM(*p))
+    while (p < e) {
+        const Py_UCS4 ch = _Py_UNICODE_NEXT(p, e);
+        if (!Py_UNICODE_ISALNUM(ch))
             return PyBool_FromLong(0);
     }
     return PyBool_FromLong(1);
@@ -7907,8 +7940,8 @@ unicode_isdecimal(PyUnicodeObject *self)
         return PyBool_FromLong(0);
 
     e = p + PyUnicode_GET_SIZE(self);
-    for (; p < e; p++) {
-        if (!Py_UNICODE_ISDECIMAL(*p))
+    while (p < e) {
+        if (!Py_UNICODE_ISDECIMAL(_Py_UNICODE_NEXT(p, e)))
             return PyBool_FromLong(0);
     }
     return PyBool_FromLong(1);
@@ -7936,8 +7969,8 @@ unicode_isdigit(PyUnicodeObject *self)
         return PyBool_FromLong(0);
 
     e = p + PyUnicode_GET_SIZE(self);
-    for (; p < e; p++) {
-        if (!Py_UNICODE_ISDIGIT(*p))
+    while (p < e) {
+        if (!Py_UNICODE_ISDIGIT(_Py_UNICODE_NEXT(p, e)))
             return PyBool_FromLong(0);
     }
     return PyBool_FromLong(1);
@@ -7965,37 +7998,22 @@ unicode_isnumeric(PyUnicodeObject *self)
         return PyBool_FromLong(0);
 
     e = p + PyUnicode_GET_SIZE(self);
-    for (; p < e; p++) {
-        if (!Py_UNICODE_ISNUMERIC(*p))
+    while (p < e) {
+        if (!Py_UNICODE_ISNUMERIC(_Py_UNICODE_NEXT(p, e)))
             return PyBool_FromLong(0);
     }
     return PyBool_FromLong(1);
 }
 
-static Py_UCS4
-decode_ucs4(const Py_UNICODE *s, Py_ssize_t *i, Py_ssize_t size)
-{
-    Py_UCS4 ch;
-    assert(*i < size);
-    ch = s[(*i)++];
-#ifndef Py_UNICODE_WIDE
-    if ((ch & 0xfffffc00) == 0xd800 &&
-        *i < size
-        && (s[*i] & 0xFFFFFC00) == 0xDC00)
-        ch = ((Py_UCS4)ch << 10UL) + (Py_UCS4)(s[(*i)++]) - 0x35fdc00;
-#endif
-    return ch;
-}
-
 int
 PyUnicode_IsIdentifier(PyObject *self)
 {
-    Py_ssize_t i = 0, size = PyUnicode_GET_SIZE(self);
-    Py_UCS4 first;
     const Py_UNICODE *p = PyUnicode_AS_UNICODE((PyUnicodeObject*)self);
+    const Py_UNICODE *e;
+    Py_UCS4 first;
 
     /* Special case for empty strings */
-    if (!size)
+    if (PyUnicode_GET_SIZE(self) == 0)
         return 0;
 
     /* PEP 3131 says that the first character must be in
@@ -8006,12 +8024,13 @@ PyUnicode_IsIdentifier(PyObject *self)
        definition of XID_Start and XID_Continue, it is sufficient
        to check just for these, except that _ must be allowed
        as starting an identifier.  */
-    first = decode_ucs4(p, &i, size);
+    e = p + PyUnicode_GET_SIZE(self);
+    first = _Py_UNICODE_NEXT(p, e);
     if (!_PyUnicode_IsXidStart(first) && first != 0x5F /* LOW LINE */)
         return 0;
 
-    while (i < size)
-        if (!_PyUnicode_IsXidContinue(decode_ucs4(p, &i, size)))
+    while (p < e)
+        if (!_PyUnicode_IsXidContinue(_Py_UNICODE_NEXT(p, e)))
             return 0;
     return 1;
 }
@@ -8046,8 +8065,8 @@ unicode_isprintable(PyObject *self)
     }
 
     e = p + PyUnicode_GET_SIZE(self);
-    for (; p < e; p++) {
-        if (!Py_UNICODE_ISPRINTABLE(*p)) {
+    while (p < e) {
+        if (!Py_UNICODE_ISPRINTABLE(_Py_UNICODE_NEXT(p, e))) {
             Py_RETURN_FALSE;
         }
     }