phases: mark `phasecache.phaseroots` private

phases: mark `phasecache.phaseroots` private

We are about to change its content from nodeid to revnum. So anyone directly
using the content might be in unexpected troubles. We start by making it private
to explicitly break any such user (and discourage them to do so).

--- a/mercurial/bundlerepo.py	Tue Feb 20 17:17:54 2024 +0100
+++ b/mercurial/bundlerepo.py	Tue Feb 20 17:18:15 2024 +0100
@@ -270,7 +270,7 @@
         raise NotImplementedError
 
     def _updateroots(self, phase, newroots, tr):
-        self.phaseroots[phase] = newroots
+        self._phaseroots[phase] = newroots
         self.invalidate()
         self.dirty = True
 

--- a/mercurial/phases.py	Tue Feb 20 17:17:54 2024 +0100
+++ b/mercurial/phases.py	Tue Feb 20 17:18:15 2024 +0100
@@ -363,7 +363,7 @@
     ):
         if _load:
             # Cheap trick to allow shallow-copy without copy module
-            self.phaseroots, self.dirty = _readroots(repo, phasedefaults)
+            self._phaseroots, self.dirty = _readroots(repo, phasedefaults)
             self._loadedrevslen = 0
             self._phasesets = None
             self.filterunknown(repo)
@@ -377,7 +377,7 @@
             self.invalidate()
             self.loadphaserevs(repo)
         return any(
-            revs for phase, revs in self.phaseroots.items() if phase != public
+            revs for phase, revs in self._phaseroots.items() if phase != public
         )
 
     def nonpublicphaseroots(
@@ -396,7 +396,7 @@
         return set().union(
             *[
                 revs
-                for phase, revs in self.phaseroots.items()
+                for phase, revs in self._phaseroots.items()
                 if phase != public
             ]
         )
@@ -464,7 +464,7 @@
         # Shallow copy meant to ensure isolation in
         # advance/retractboundary(), nothing more.
         ph = self.__class__(None, None, _load=False)
-        ph.phaseroots = self.phaseroots.copy()
+        ph._phaseroots = self._phaseroots.copy()
         ph.dirty = self.dirty
         ph.opener = self.opener
         ph._loadedrevslen = self._loadedrevslen
@@ -474,7 +474,7 @@
     def replace(self, phcache):
         """replace all values in 'self' with content of phcache"""
         for a in (
-            'phaseroots',
+            '_phaseroots',
             'dirty',
             'opener',
             '_loadedrevslen',
@@ -484,7 +484,7 @@
 
     def _getphaserevsnative(self, repo):
         repo = repo.unfiltered()
-        return repo.changelog.computephases(self.phaseroots)
+        return repo.changelog.computephases(self._phaseroots)
 
     def _computephaserevspure(self, repo):
         repo = repo.unfiltered()
@@ -492,7 +492,7 @@
         self._phasesets = {phase: set() for phase in allphases}
         lowerroots = set()
         for phase in reversed(trackedphases):
-            roots = pycompat.maplist(cl.rev, self.phaseroots[phase])
+            roots = pycompat.maplist(cl.rev, self._phaseroots[phase])
             if roots:
                 ps = set(cl.descendants(roots))
                 for root in roots:
@@ -543,13 +543,13 @@
             f.close()
 
     def _write(self, fp):
-        for phase, roots in self.phaseroots.items():
+        for phase, roots in self._phaseroots.items():
             for h in sorted(roots):
                 fp.write(b'%i %s\n' % (phase, hex(h)))
         self.dirty = False
 
     def _updateroots(self, phase, newroots, tr):
-        self.phaseroots[phase] = newroots
+        self._phaseroots[phase] = newroots
         self.invalidate()
         self.dirty = True
 
@@ -598,7 +598,7 @@
             if not revs:
                 break  # no roots to move anymore
 
-            olds = self.phaseroots[phase]
+            olds = self._phaseroots[phase]
 
             affected = repo.revs(b'%ln::%ld', olds, revs)
             changes.update(affected)
@@ -627,7 +627,7 @@
     def retractboundary(self, repo, tr, targetphase, nodes):
         oldroots = {
             phase: revs
-            for phase, revs in self.phaseroots.items()
+            for phase, revs in self._phaseroots.items()
             if phase <= targetphase
         }
         if tr is None:
@@ -641,7 +641,7 @@
         ):
 
             # find the affected revisions
-            new = self.phaseroots[targetphase]
+            new = self._phaseroots[targetphase]
             old = oldroots[targetphase]
             affected = set(repo.revs(b'(%ln::) - (%ln::)', new, old))
 
@@ -675,7 +675,7 @@
         repo = repo.unfiltered()
         torev = repo.changelog.rev
         tonode = repo.changelog.node
-        currentroots = {torev(node) for node in self.phaseroots[targetphase]}
+        currentroots = {torev(node) for node in self._phaseroots[targetphase]}
         finalroots = oldroots = set(currentroots)
         newroots = [torev(node) for node in nodes] + [r for r in revs]
         newroots = [
@@ -714,7 +714,7 @@
         """
         assert repo.filtername is None
         to_rev = repo.changelog.index.rev
-        for targetphase, nodes in list(self.phaseroots.items()):
+        for targetphase, nodes in list(self._phaseroots.items()):
             filtered = {n for n in nodes if to_rev(n) >= strip_rev}
             if filtered:
                 self._updateroots(targetphase, nodes - filtered, tr)
@@ -727,7 +727,7 @@
         """
         filtered = False
         has_node = repo.changelog.index.has_node  # to filter unknown nodes
-        for phase, nodes in self.phaseroots.items():
+        for phase, nodes in self._phaseroots.items():
             missing = sorted(node for node in nodes if not has_node(node))
             if missing:
                 for mnode in missing:
@@ -803,7 +803,7 @@
     keys = util.sortdict()
     value = b'%i' % draft
     cl = repo.unfiltered().changelog
-    for root in repo._phasecache.phaseroots[draft]:
+    for root in repo._phasecache._phaseroots[draft]:
         if repo._phasecache.phase(repo, cl.rev(root)) <= draft:
             keys[hex(root)] = value
 
@@ -997,7 +997,7 @@
 
 def hassecret(repo: "localrepo.localrepository") -> bool:
     """utility function that check if a repo have any secret changeset."""
-    return bool(repo._phasecache.phaseroots[secret])
+    return bool(repo._phasecache._phaseroots[secret])
 
 
 def preparehookargs(