Moved BytesIO into compat because of py25 compatibility issue

rhodecode/lib/compat.py

@@ -394,3 +394,13 b' except ImportError:'
             result = [x + [y] for x in result for y in pool]
         for prod in result:
             yield tuple(prod)
+
+
+#==============================================================================
+# BytesIO
+#==============================================================================
+
+try:
+    from io import BytesIO
+except ImportError:
+    from cStringIO import StringIO as BytesIO

rhodecode/lib/diffs.py

@@ -26,7 +26,6 b''
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import re
-import io
 import difflib
 import markupsafe
 
@@ -39,6 +38,7 b' from mercurial import localrepo'
 
 from pylons.i18n.translation import _
 
+from rhodecode.lib.compat import BytesIO
 from rhodecode.lib.vcs.exceptions import VCSError
 from rhodecode.lib.vcs.nodes import FileNode, SubModuleNode
 from rhodecode.lib.helpers import escape
@@ -603,7 +603,7 b' def differ(org_repo, org_ref, other_repo'
             unbundle = other_repo.getbundle('incoming', common=common,
                                             heads=rheads)
 
-            buf = io.BytesIO()
+            buf = BytesIO()
             while True:
                 chunk = unbundle._stream.read(1024 * 4)
                 if not chunk: