largefiles: call readstandin() with changectx itself instead of rev or node

largefiles: call readstandin() with changectx itself instead of rev or node

readstandin() takes "node" argument to get changectx by "repo[node]".

There are some readstandin() invocations, which use ctx.node(),
ctx.rev(), or '.' as "node" argument above, even though corresponded
changectx object is already looked up on caller side.

This patch calls readstandin() with already known changectx itself, to
avoid meaningless re-construction of changectx (indirect case via
copytostore() is also included).

BTW, copytostore() uses "rev" argument only for readstandin()
invocation. Therefore, this patch also renames it to "revorctx" to
indicate that it can take not only revision ID or so but also
changectx, for readability.

--- a/hgext/largefiles/lfutil.py	Fri Mar 24 22:24:59 2017 +0900
+++ b/hgext/largefiles/lfutil.py	Fri Mar 24 22:26:34 2017 +0900
@@ -245,9 +245,9 @@
         return False
     return True
 
-def copytostore(repo, rev, file, uploaded=False):
+def copytostore(repo, revorctx, file, uploaded=False):
     wvfs = repo.wvfs
-    hash = readstandin(repo, file, rev)
+    hash = readstandin(repo, file, revorctx)
     if instore(repo, hash):
         return
     if wvfs.exists(file):
@@ -263,7 +263,7 @@
     for filename in ctx.files():
         realfile = splitstandin(filename)
         if realfile is not None and filename in ctx.manifest():
-            copytostore(repo, ctx.node(), realfile)
+            copytostore(repo, ctx, realfile)
 
 def copytostoreabsolute(repo, file, hash):
     if inusercache(repo.ui, hash):
@@ -485,6 +485,11 @@
     lfdirstate.write()
 
     # As part of committing, copy all of the largefiles into the cache.
+    #
+    # Using "node" instead of "ctx" implies additional "repo[node]"
+    # lookup while copyalltostore(), but can omit redundant check for
+    # files comming from the 2nd parent, which should exist in store
+    # at merging.
     copyalltostore(repo, node)
 
 def getlfilestoupdate(oldstandins, newstandins):

--- a/hgext/largefiles/overrides.py	Fri Mar 24 22:24:59 2017 +0900
+++ b/hgext/largefiles/overrides.py	Fri Mar 24 22:26:34 2017 +0900
@@ -1354,7 +1354,7 @@
                     data = repo.wwritedata(f, data)
                 fp.write(data)
             else:
-                hash = lfutil.readstandin(repo, lf, ctx.rev())
+                hash = lfutil.readstandin(repo, lf, ctx)
                 if not lfutil.inusercache(repo.ui, hash):
                     store = storefactory.openstore(repo)
                     success, missing = store.get([(lf, hash)])
@@ -1405,7 +1405,7 @@
             lfutil.writestandin(repo, standin, lfhash,
                                 lfutil.getexecutable(lfileabs))
             if (standin in pctx and
-                lfhash == lfutil.readstandin(repo, lfile, '.')):
+                lfhash == lfutil.readstandin(repo, lfile, pctx)):
                 oldclean.add(lfile)
         for lfile in s.added:
             lfutil.updatestandin(repo, lfutil.standin(lfile))