[PATCH 2 of 2] convert: execute merges in-memory (issue5076)

[Tony Tung]

# HG changeset patch
# User Tony Tung <tonytung at merly.org>
# Date 1456215137 28800
#      Tue Feb 23 00:12:17 2016 -0800
# Node ID b7f61d7438ba1aed06afa1a53a2b5fda8bdc225f
# Parent  cbc605f28b61cc469e21186982d0569bf94f7d2a
convert: execute merges in-memory (issue5076)

Typically during merging two manifests, we detect if a subrepo is dirty
(i.e., the working directory differs from the hgsubstate).  If it is, we
mark it in the manifest.

When we are doing repo conversions, we do not change the working
directory.  All the changes are happening in-memory, and as such, the
computed substate will always mismatch.  This patch adds a flag to the
manifest merge logic to treat wctx as not a directory.

This is an alternate fix.  The original proposed fix was sent as
https://www.mercurial-scm.org/pipermail/mercurial-devel/2016-February/079733.html

diff --git a/hgext/convert/hg.py b/hgext/convert/hg.py
--- a/hgext/convert/hg.py
+++ b/hgext/convert/hg.py
@@ -194,6 +194,7 @@
             True,  # force
             False, # acceptremote
             False, # followcopies
+            inmemoryonly=True,
         )
 
         for file, (action, info, msg) in actions.iteritems():
diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -769,13 +769,16 @@
     return True
 
 def manifestmerge(repo, wctx, p2, pa, branchmerge, force, matcher,
-                  acceptremote, followcopies):
+                  acceptremote, followcopies, inmemoryonly):
     """
     Merge p1 and p2 with ancestor pa and generate merge action list
 
     branchmerge and force are as passed in to update
     matcher = matcher to filter file lists
     acceptremote = accept the incoming changes without prompting
+    inmemoryonly = merge is happening in memory only; wctx does not
+                   represent an actual working directory.  an example
+                   of this would be repository conversion (convert extension).
     """
     if matcher is not None and matcher.always():
         matcher = None
@@ -799,7 +802,7 @@
     copied = set(copy.values())
     copied.update(movewithdir.values())
 
-    if '.hgsubstate' in m1:
+    if not inmemoryonly and '.hgsubstate' in m1:
         # check whether sub state is modified
         for s in sorted(wctx.substate):
             if wctx.sub(s).dirty():
@@ -931,12 +934,12 @@
 
 def calculateupdates(repo, wctx, mctx, ancestors, branchmerge, force,
                      acceptremote, followcopies, matcher=None,
-                     mergeforce=False):
+                     mergeforce=False, inmemoryonly=False):
     "Calculate the actions needed to merge mctx into wctx using ancestors"
     if len(ancestors) == 1: # default
         actions, diverge, renamedelete = manifestmerge(
             repo, wctx, mctx, ancestors[0], branchmerge, force, matcher,
-            acceptremote, followcopies)
+            acceptremote, followcopies, inmemoryonly)
         _checkunknownfiles(repo, wctx, mctx, force, actions, mergeforce)
 
     else: # only when merge.preferancestor=* - the default
@@ -951,7 +954,7 @@
             repo.ui.note(_('\ncalculating bids for ancestor %s\n') % ancestor)
             actions, diverge1, renamedelete1 = manifestmerge(
                 repo, wctx, mctx, ancestor, branchmerge, force, matcher,
-                acceptremote, followcopies)
+                acceptremote, followcopies, inmemoryonly)
             _checkunknownfiles(repo, wctx, mctx, force, actions, mergeforce)
 
             # Track the shortest set of warning on the theory that bid