Make StringIO work in non-unicode builds.

Lots of tests fail in non-unicode builds, but I think most of these are
"bugs" in the tests.  I hope so, anyway.

Lib/StringIO.py

@@ -39,7 +39,7 @@ __all__ = ["StringIO"]
 class StringIO:
     def __init__(self, buf = ''):
         # Force self.buf to be a string or unicode
-        if type(buf) is not types.UnicodeType:
+        if type(buf) not in types.StringTypes:
             buf = str(buf)
         self.buf = buf
         self.len = len(buf)
@@ -138,7 +138,7 @@ class StringIO:
             raise ValueError, "I/O operation on closed file"
         if not s: return
         # Force s to be a string or unicode
-        if type(s) is not types.UnicodeType:
+        if type(s) not in types.StringTypes:
             s = str(s)
         if self.pos > self.len:
             self.buflist.append('\0'*(self.pos - self.len))

Lib/test/test_StringIO.py

@@ -71,20 +71,21 @@ class TestGenericStringIO(unittest.TestCase):
 class TestStringIO(TestGenericStringIO):
     MODULE = StringIO
 
-    def test_unicode(self):
+    if test_support.have_unicode:
+        def test_unicode(self):
 
-        # The StringIO module also supports concatenating Unicode
-        # snippets to larger Unicode strings. This is tested by this
-        # method. Note that cStringIO does not support this extension.
+            # The StringIO module also supports concatenating Unicode
+            # snippets to larger Unicode strings. This is tested by this
+            # method. Note that cStringIO does not support this extension.
         
-        f = self.MODULE.StringIO()
-        f.write(self._line[:6])
-        f.seek(3)
-        f.write(unicode(self._line[20:26]))
-        f.write(unicode(self._line[52]))
-        s = f.getvalue()
-        self.assertEqual(s, unicode('abcuvwxyz!'))
-        self.assertEqual(type(s), types.UnicodeType)
+            f = self.MODULE.StringIO()
+            f.write(self._line[:6])
+            f.seek(3)
+            f.write(unicode(self._line[20:26]))
+            f.write(unicode(self._line[52]))
+            s = f.getvalue()
+            self.assertEqual(s, unicode('abcuvwxyz!'))
+            self.assertEqual(type(s), types.UnicodeType)
 
 class TestcStringIO(TestGenericStringIO):
     MODULE = cStringIO