D4874: treemanifests: store whether a lazydirs entry needs copied after materializing

[spectral (Kyle Lippincott)]

spectral created this revision.
Herald added a subscriber: mercurial-devel.
Herald added a reviewer: hg-reviewers.

REVISION SUMMARY
  Due to the way that things like manifestlog.get caches its values, without
  making a copy (if necessary) after calling readsubtree(), we might end up
  adjusting the state of the same object on different contexts, breaking things
  like dirty state tracking (and probably other things).

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D4874

AFFECTED FILES
  mercurial/manifest.py

CHANGE DETAILS

diff --git a/mercurial/manifest.py b/mercurial/manifest.py
--- a/mercurial/manifest.py
+++ b/mercurial/manifest.py
@@ -701,15 +701,22 @@
         return self._dir + path
 
     def _loadalllazy(self):
-        for k, (path, node, readsubtree) in self._lazydirs.iteritems():
-            self._dirs[k] = readsubtree(path, node)
+        selfdirs = self._dirs
+        for d, (path, node, readsubtree, docopy) in self._lazydirs.iteritems():
+            if docopy:
+                selfdirs[d] = readsubtree(path, node).copy()
+            else:
+                selfdirs[d] = readsubtree(path, node)
         self._lazydirs = {}
 
     def _loadlazy(self, d):
         v = self._lazydirs.get(d)
         if v:
-            path, node, readsubtree = v
-            self._dirs[d] = readsubtree(path, node)
+            path, node, readsubtree, docopy = v
+            if docopy:
+                self._dirs[d] = readsubtree(path, node).copy()
+            else:
+                self._dirs[d] = readsubtree(path, node)
             del self._lazydirs[d]
 
     def _loadchildrensetlazy(self, visit):
@@ -1170,7 +1177,9 @@
         for f, n, fl in _parse(text):
             if fl == 't':
                 f = f + '/'
-                selflazy[f] = (subpath(f), n, readsubtree)
+                # False below means "doesn't need to be copied" and can use the
+                # cached value from readsubtree directly.
+                selflazy[f] = (subpath(f), n, readsubtree, False)
             elif '/' in f:
                 # This is a flat manifest, so use __setitem__ and setflag rather
                 # than assigning directly to _files and _flags, so we can
@@ -1197,8 +1206,7 @@
         """
         self._load()
         flags = self.flags
-        lazydirs = [(d[:-1], node, 't') for
-                    d, (path, node, readsubtree) in self._lazydirs.iteritems()]
+        lazydirs = [(d[:-1], v[1], 't') for d, v in self._lazydirs.iteritems()]
         dirs = [(d[:-1], self._dirs[d]._node, 't') for d in self._dirs]
         files = [(f, self._files[f], flags(f)) for f in self._files]
         return _text(sorted(dirs + files + lazydirs))



To: spectral, #hg-reviewers
Cc: mercurial-devel