# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@octobus.net>
# Date 1494514723 -7200
# Node ID 34c6382dbb822352a4113b36e80e63452edaa2d9
# Parent  406c1a57b4ee2bb3c098f8abecffbc6c6cdb5494
obscache: guard from changing changelog or obsstore object

We access these object once to make sure they will never change through the
function (and their content will be fixed).

diff -r 406c1a57b4ee -r 34c6382dbb82 hgext3rd/evolve/obscache.py
--- a/hgext3rd/evolve/obscache.py	Thu May 11 16:45:13 2017 +0200
+++ b/hgext3rd/evolve/obscache.py	Thu May 11 16:58:43 2017 +0200
@@ -99,7 +99,11 @@
                      up to date.
     """
 
-    # XXX we need to ensure we use the same changelog and obsstore through the processing
+    # We need to ensure we use the same changelog and obsstore through the
+    # processing. Otherwise some invalidation could update the object and their
+    # content after we computed the cache key.
+    cl = repo.changelog
+    obsstore = repo.obsstore
 
     reset = False
 
@@ -107,8 +111,8 @@
     if status is None:
         reset = True
         key = emptykey
-        obssize, obskey = repo.obsstore.cachekey()
-        tiprev = len(repo.changelog) - 1
+        obssize, obskey = obsstore.cachekey()
+        tiprev = len(cl) - 1
     else:
         tiprev, obssize, obskey = status
 
@@ -122,7 +126,7 @@
     # any new changesets ?
     revs = ()
     if keytiprev < tiprev:
-        revs = list(repo.changelog.revs(start=keytiprev + 1, stop=tiprev))
+        revs = list(cl.revs(start=keytiprev + 1, stop=tiprev))
 
     # any new markers
     markers = ()
@@ -136,7 +140,7 @@
         # In pratice the cache is only updated after each transaction within a
         # lock. So we should be fine. We could enforce this with a new repository
         # requirement (or fix the race, that is not too hard).
-        markers = markersfrom(repo.obsstore, keyobssize, keyobslength)
+        markers = markersfrom(obsstore, keyobssize, keyobslength)
 
     return reset, revs, markers, (obssize, obskey)