Fixed #15644 -- Improved Django File wrapper to support more file-like objects. Thanks nickname123 and Michael Palumbo for working on the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17871 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/files/base.py

@@ -36,8 +36,13 @@ class File(FileProxyMixin):
         if not hasattr(self, '_size'):
             if hasattr(self.file, 'size'):
                 self._size = self.file.size
-            elif os.path.exists(self.file.name):
+            elif hasattr(self.file, 'name') and os.path.exists(self.file.name):
                 self._size = os.path.getsize(self.file.name)
+            elif hasattr(self.file, 'tell') and hasattr(self.file, 'seek'):
+                pos = self.file.tell()
+                self.file.seek(0, os.SEEK_END)
+                self._size = self.file.tell()
+                self.file.seek(pos)
             else:
                 raise AttributeError("Unable to determine the file's size.")
         return self._size
@@ -61,12 +66,12 @@ class File(FileProxyMixin):
 
         if hasattr(self, 'seek'):
             self.seek(0)
-        # Assume the pointer is at zero...
-        counter = self.size
 
-        while counter > 0:
-            yield self.read(chunk_size)
-            counter -= chunk_size
+        while True:
+            data = self.read(chunk_size)
+            if not data:
+                break
+            yield data
 
     def multiple_chunks(self, chunk_size=None):
         """