Replace file class by Python 3 compatible io classes.

src/App/tests/testImageFile.py

-import unittest
+import io
 import os.path
+from StringIO import StringIO
+import unittest
+
 import App
 from Testing.ZopeTestCase.warnhook import WarningsHook
+from ZPublisher.HTTPRequest import WSGIRequest
+from ZPublisher.HTTPResponse import WSGIResponse
 
 
 class TestImageFile(unittest.TestCase):
@@ -39,3 +44,26 @@ class TestImageFile(unittest.TestCase):
         prefix = App.__dict__
         App.ImageFile.ImageFile('www/zopelogo.png', prefix)
         self.assertFalse(self.warningshook.warnings)
+
+
+class TestImageFileFunctional(unittest.TestCase):
+
+    def test_index_html(self):
+        env = {
+            'SERVER_NAME': 'localhost',
+            'SERVER_PORT': '80',
+            'SERVER_PROTOCOL': 'HTTP/1.1',
+            'REQUEST_METHOD': 'GET',
+        }
+        stdin = StringIO()
+        stdout = StringIO()
+        response = WSGIResponse(stdout)
+        request = WSGIRequest(stdin, env, response)
+        path = os.path.join(os.path.dirname(App.__file__),
+                            'www', 'zopelogo.png')
+        image = App.ImageFile.ImageFile(path)
+        result = image.index_html(request, response)
+        self.assertEqual(stdout.getvalue(), '')
+        self.assertTrue(isinstance(result, io.FileIO))
+        self.assertTrue(b''.join(result).startswith(b'\x89PNG\r\n'))
+        self.assertEqual(len(result), image.size)

src/OFS/tests/testFileAndImage.py

@@ -273,7 +273,10 @@ class ImageTests(FileTests):
         self.assertEqual(self.file.tag(), (tag_fmt % ('bar', 'foo')))
 
     def testViewImageOrFile(self):
-        pass  # dtml method,screw it
+        request = self.app.REQUEST
+        response = request.RESPONSE
+        result = self.file.index_html(request, response)
+        self.assertEqual(result, self.data)
 
     def test_interfaces(self):
         from zope.interface.verify import verifyClass

src/ZPublisher/Iterators.py

+import io
+
 from zope.interface import Interface
 from zope.interface import implements
 
@@ -36,16 +38,16 @@ class IStreamIterator(IUnboundStreamIterator):
         """
 
 
-class filestream_iterator(file):
+class filestream_iterator(io.FileIO):
     """
-    a file subclass which implements an iterator that returns a
+    A FileIO subclass which implements an iterator that returns a
     fixed-sized sequence of bytes.
     """
 
     implements(IStreamIterator)
 
-    def __init__(self, name, mode='r', bufsize=-1, streamsize=1 << 16):
-        file.__init__(self, name, mode, bufsize)
+    def __init__(self, name, mode='rb', bufsize=-1, streamsize=1 << 16):
+        super(filestream_iterator, self).__init__(name, mode)
         self.streamsize = streamsize
 
     def next(self):
@@ -56,7 +58,7 @@ class filestream_iterator(file):
 
     def __len__(self):
         cur_pos = self.tell()
-        self.seek(0, 2)
+        self.seek(0, io.SEEK_END)
         size = self.tell()
-        self.seek(cur_pos, 0)
+        self.seek(cur_pos, io.SEEK_SET)
         return size

src/ZPublisher/WSGIPublisher.py

@@ -14,6 +14,7 @@
 """
 from contextlib import contextmanager, closing
 from cStringIO import StringIO
+from io import IOBase
 import sys
 from thread import allocate_lock
 
@@ -40,9 +41,9 @@ from ZPublisher import pubevents
 from ZPublisher.utils import recordMetaData
 
 if sys.version_info >= (3, ):
-    from io import IOBase
+    _FILE_TYPES = (IOBase, )
 else:
-    IOBase = file  # NOQA
+    _FILE_TYPES = (IOBase, file)  # NOQA
 
 _DEFAULT_DEBUG_MODE = False
 _DEFAULT_REALM = None
@@ -229,7 +230,7 @@ def publish_module(environ, start_response,
         status, headers = response.finalize()
         start_response(status, headers)
 
-        if (isinstance(response.body, IOBase) or
+        if (isinstance(response.body, _FILE_TYPES) or
                 IUnboundStreamIterator.providedBy(response.body)):
             result = response.body
         else:

src/ZPublisher/tests/test_WSGIPublisher.py

@@ -320,8 +320,9 @@ class TestPublishModule(unittest.TestCase, PlacelessSetup):
         self.assertEqual(kw, {})
 
     def test_response_body_is_file(self):
+        from io import BytesIO
 
-        class DummyFile(file):
+        class DummyFile(BytesIO):
             def __init__(self):
                 pass