D11012: dirstate: add a function to update tracking status while "moving" parent

[marmoute (Pierre-Yves David)]

marmoute created this revision.
Herald added a reviewer: hg-reviewers.
Herald added a subscriber: mercurial-patches.

REVISION SUMMARY
  The `scmutil.dirstateparent` is moving the dirstate parent without touching the
  working copy. It isi used by history rewriting operation like amending of
  folding.
  
  The function was doing "low level" computation and dirstate updating itself.
  All that logic belong to the dirstate and should be moved there.
  
  For this purpose we introduce a new function that does just that and use it.

REPOSITORY
  rHG Mercurial

BRANCH
  default

REVISION DETAIL
  https://phab.mercurial-scm.org/D11012

AFFECTED FILES
  mercurial/dirstate.py
  mercurial/scmutil.py

CHANGE DETAILS

diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py
--- a/mercurial/scmutil.py
+++ b/mercurial/scmutil.py
@@ -1485,25 +1485,15 @@
     copies = dict(ds.copies())
     ds.setparents(newctx.node(), repo.nullid)
     s = newctx.status(oldctx, match=match)
+
     for f in s.modified:
-        if ds[f] == b'r':
-            # modified + removed -> removed
-            continue
-        ds.normallookup(f)
+        ds.update_file_reference(f, p1_tracked=True)
 
     for f in s.added:
-        if ds[f] == b'r':
-            # added + removed -> unknown
-            ds.drop(f)
-        elif ds[f] != b'a':
-            ds.add(f)
+        ds.update_file_reference(f, p1_tracked=False)
 
     for f in s.removed:
-        if ds[f] == b'a':
-            # removed + added -> normal
-            ds.normallookup(f)
-        elif ds[f] != b'r':
-            ds.remove(f)
+        ds.update_file_reference(f, p1_tracked=True)
 
     # Merge old parent and old working dir copies
     oldcopies = copiesmod.pathcopies(newctx, oldctx, match)
diff --git a/mercurial/dirstate.py b/mercurial/dirstate.py
--- a/mercurial/dirstate.py
+++ b/mercurial/dirstate.py
@@ -440,6 +440,49 @@
     def copies(self):
         return self._map.copymap
 
+    def update_file_reference(
+        self,
+        filename,
+        p1_tracked,
+    ):
+        """Set a file as tracked in the parent (or not)
+
+        Thi is to be called when adjust the dirstate to a new parent after an history
+        rewriing operation.
+
+        As per its function, it should not be called during a merge (p2 !=
+        nullid) and only withing a `with dirstate.parentchange():` context.
+        """
+        if self._parentwriters <= 0:
+            msg = (
+                b'calling update_file_reference outside'
+                b' of a parentchange context'
+            )
+            raise error.ProgrammingError(msg)
+        elif self.in_merge:
+            msg = b'update_file_reference should not be called when merging'
+            raise error.ProgrammingError(msg)
+        entry = self._map.get(filename)
+        if entry is None:
+            wc_tracked = False
+        else:
+            wc_tracked = entry.tracked
+        if p1_tracked and wc_tracked:
+            # the underlying reference might have changed, we will have to
+            # check it.
+            self.normallookup(filename)
+        elif not (p1_tracked or wc_tracked):
+            # the file is no longer relevant to anyone
+            self.drop(filename)
+        elif (not p1_tracked) and wc_tracked:
+            if not entry.added:
+                self._add(filename)
+        elif p1_tracked and not wc_tracked:
+            if entry is None or not entry.removed:
+                self._remove(filename)
+        else:
+            assert False, 'unreachable'
+
     def _addpath(
         self,
         f,



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