[Reviewers] [Differential] [Request, 70 lines] D26: rebase: remove revprecursor and revpruned states

[quark (Jun Wu)]

quark created this revision.
Herald added a subscriber: reviewers.

REVISION SUMMARY
  They are no longer necessary to make rebase behavior correct. Therefore
  remove them to make the code cleaner and easier to reason about.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D26

AFFECTED FILES
  hgext/rebase.py

CHANGE DETAILS

Index: hgext/rebase.py
===================================================================
--- hgext/rebase.py
+++ hgext/rebase.py
@@ -60,12 +60,10 @@
 
 # Indicates that a revision needs to be rebased
 revtodo = -1
-nullmerge = -2
-revignored = -3
 
 # legacy revstates no longer needed in current code
-# -4: revprecursor, -5: revpruned
-legacystates = {'-4', '-5'}
+# -2: nullmerge, -3: revignored, -4: revprecursor, -5: revpruned
+legacystates = {'-2', '-3', '-4', '-5'}
 
 cmdtable = {}
 command = registrar.command(cmdtable)
@@ -233,8 +231,6 @@
                     oldrev, newrev = l.split(':')
                     if newrev in legacystates:
                         continue
-                    if newrev in (str(nullmerge), str(revignored)):
-                        state[repo[oldrev].rev()] = int(newrev)
                     elif newrev == nullid:
                         state[repo[oldrev].rev()] = revtodo
                         # Legacy compat special case
@@ -439,10 +435,6 @@
                         self.skipped.add(rev)
                     self.state[rev] = p1
                     ui.debug('next revision set to %s\n' % p1)
-            elif self.state[rev] == nullmerge:
-                pass
-            elif self.state[rev] == revignored:
-                pass
             else:
                 ui.status(_('already rebased %s as %s\n') %
                           (desc, repo[self.state[rev]]))
@@ -463,7 +455,7 @@
                 commitmsg = 'Collapsed revision'
                 for rebased in self.state:
                     if rebased not in self.skipped and\
-                       self.state[rebased] > nullmerge:
+                       self.state[rebased] >= revtodo:
                         commitmsg += '\n* %s' % repo[rebased].description()
                 editopt = True
             editor = cmdutil.getcommiteditor(edit=editopt, editform=editform)
@@ -479,7 +471,7 @@
             else:
                 newrev = repo[newnode].rev()
             for oldrev in self.state.iterkeys():
-                if self.state[oldrev] > nullmerge:
+                if self.state[oldrev] >= revtodo:
                     self.state[oldrev] = newrev
 
         if 'qtip' in repo.tags():
@@ -1230,7 +1222,6 @@
         raise error.Abort(_('no matching revisions'))
     roots.sort()
     state = dict.fromkeys(rebaseset, revtodo)
-    detachset = set()
     emptyrebase = True
     for root in roots:
         commonbase = root.ancestor(dest)
@@ -1252,66 +1243,13 @@
 
         emptyrebase = False
         repo.ui.debug('rebase onto %s starting from %s\n' % (dest, root))
-        # Rebase tries to turn <dest> into a parent of <root> while
-        # preserving the number of parents of rebased changesets:
-        #
-        # - A changeset with a single parent will always be rebased as a
-        #   changeset with a single parent.
-        #
-        # - A merge will be rebased as merge unless its parents are both
-        #   ancestors of <dest> or are themselves in the rebased set and
-        #   pruned while rebased.
-        #
-        # If one parent of <root> is an ancestor of <dest>, the rebased
-        # version of this parent will be <dest>. This is always true with
-        # --base option.
-        #
-        # Otherwise, we need to *replace* the original parents with
-        # <dest>. This "detaches" the rebased set from its former location
-        # and rebases it onto <dest>. Changes introduced by ancestors of
-        # <root> not common with <dest> (the detachset, marked as
-        # nullmerge) are "removed" from the rebased changesets.
-        #
-        # - If <root> has a single parent, set it to <dest>.
-        #
-        # - If <root> is a merge, we cannot decide which parent to
-        #   replace, the rebase operation is not clearly defined.
-        #
-        # The table below sums up this behavior:
-        #
-        # +------------------+----------------------+-------------------------+
-        # |                  |     one parent       |  merge                  |
-        # +------------------+----------------------+-------------------------+
-        # | parent in        | new parent is <dest> | parents in ::<dest> are |
-        # | ::<dest>         |                      | remapped to <dest>      |
-        # +------------------+----------------------+-------------------------+
-        # | unrelated source | new parent is <dest> | ambiguous, abort        |
-        # +------------------+----------------------+-------------------------+
-        #
-        # The actual abort is handled by `defineparents`
-        if len(root.parents()) <= 1:
-            # ancestors of <root> not ancestors of <dest>
-            detachset.update(repo.changelog.findmissingrevs([commonbase.rev()],
-                                                            [root.rev()]))
     if emptyrebase:
         return None
     for rev in sorted(state):
         parents = [p for p in repo.changelog.parentrevs(rev) if p != nullrev]
         # if all parents of this revision are done, then so is this revision
         if parents and all((state.get(p) == p for p in parents)):
             state[rev] = rev
-    for r in detachset:
-        if r not in state:
-            state[r] = nullmerge
-    if len(roots) > 1:
-        # If we have multiple roots, we may have "hole" in the rebase set.
-        # Rebase roots that descend from those "hole" should not be detached as
-        # other root are. We use the special `revignored` to inform rebase that
-        # the revision should be ignored but that `defineparents` should search
-        # a rebase destination that make sense regarding rebased topology.
-        rebasedomain = set(repo.revs('%ld::%ld', rebaseset, rebaseset))
-        for ignored in set(rebasedomain) - set(rebaseset):
-            state[ignored] = revignored
     unfi = repo.unfiltered()
     for r in obsoletenotrebased:
         desc = _ctxdesc(unfi[r])


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