remotefilelog: cast division result to an int

Otherwise mid is a float and this confuses __slice__ on Python 3.

Differential Revision: https://phab.mercurial-scm.org/D5760

contrib/python3-whitelist

@@ -588,6 +588,7 b' test-remotefilelog-bundles.t'
 test-remotefilelog-cacheprocess.t
 test-remotefilelog-clone-tree.t
 test-remotefilelog-clone.t
+test-remotefilelog-datapack.py
 test-remotefilelog-gcrepack.t
 test-remotefilelog-histpack.py
 test-remotefilelog-http.t

hgext/remotefilelog/datapack.py

@@ -243,7 +243,7 b' class datapack(basepack.basepack):'
         else:
             while start < end - entrylen:
                 mid = start  + (end - start) / 2
-                mid = mid - ((mid - params.indexstart) % entrylen)
+                mid = int(mid - ((mid - params.indexstart) % entrylen))
                 midnode = index[mid:mid + NODELENGTH]
                 if midnode == node:
                     entry = index[mid:mid + entrylen]