lfs: ensure that the return of urlopener.open() is closed

No problem observed, just an oversight noticed while reading documentation.

hgext/lfs/blobstore.py

@@ -7,6 +7,7 b''
 
 from __future__ import absolute_import
 
+import contextlib
 import errno
 import hashlib
 import json
@@ -297,7 +298,7 b' class _gitlfsremote(object):'
         batchreq.add_header('Accept', 'application/vnd.git-lfs+json')
         batchreq.add_header('Content-Type', 'application/vnd.git-lfs+json')
         try:
-            rsp = self.urlopener.open(batchreq)
+            with contextlib.closing(self.urlopener.open(batchreq)) as rsp:
             rawjson = rsp.read()
         except util.urlerr.httperror as ex:
             hints = {
@@ -419,16 +420,18 b' class _gitlfsremote(object):'
 
         response = b''
         try:
-            req = self.urlopener.open(request)
-
+            with contextlib.closing(self.urlopener.open(request)) as req:
+                ui = self.ui  # Shorten debug lines
             if self.ui.debugflag:
-                self.ui.debug('Status: %d\n' % req.status)
-                # lfs-test-server and hg serve return headers in different order
-                self.ui.debug('%s\n'
+                    ui.debug('Status: %d\n' % req.status)
+                    # lfs-test-server and hg serve return headers in different
+                    # order
+                    ui.debug('%s\n'
                               % '\n'.join(sorted(str(req.info()).splitlines())))
 
             if action == 'download':
-                # If downloading blobs, store downloaded data to local blobstore
+                    # If downloading blobs, store downloaded data to local
+                    # blobstore
                 localstore.download(oid, req)
             else:
                 while True:
@@ -437,7 +440,7 b' class _gitlfsremote(object):'
                         break
                     response += data
                 if response:
-                    self.ui.debug('lfs %s response: %s' % (action, response))
+                        ui.debug('lfs %s response: %s' % (action, response))
         except util.urlerr.httperror as ex:
             if self.ui.debugflag:
                 self.ui.debug('%s: %s\n' % (oid, ex.read()))