Patchwork D10518: rewriteutil: check for divergence

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Submitter phabricator
Date April 28, 2021, 3:08 p.m.
Message ID <differential-rev-PHID-DREV-vbct6jujeaob47gphelg-req@mercurial-scm.org>
Download mbox | patch
Permalink /patch/48848/
State Superseded
Headers show

Comments

phabricator - April 28, 2021, 3:08 p.m.
martinvonz created this revision.
Herald added a reviewer: hg-reviewers.
Herald added a subscriber: mercurial-patches.
martinvonz edited the summary of this revision.
pulkit added inline comments.
pulkit accepted this revision.
This revision is now accepted and ready to land.

INLINE COMMENTS

> test-branch-change.t:153
>    $ hg branch -r 4 --hidden foobar
> -  abort: cannot change branch of a obsolete changeset
> +  abort: change branch of of 3938acfb5c0f creates content-divergence with 7c1991464886
> +  (add --verbose for details)

`s/of of/ of`

REVISION SUMMARY
  This code is adapted from the code in the evolve extension. It seems
  to be equivalent as far as the evolve extension's test suite can tell
  (the only impact when making their `precheck()` delegate to our
  version is that error messages are less detailed).

REPOSITORY
  rHG Mercurial

BRANCH
  default

REVISION DETAIL
  https://phab.mercurial-scm.org/D10518

AFFECTED FILES
  hgext/rebase.py
  mercurial/obsolete.py
  mercurial/rewriteutil.py
  tests/test-amend.t
  tests/test-branch-change.t
  tests/test-obshistory.t
  tests/test-obsmarker-template.t
  tests/test-unamend.t

CHANGE DETAILS




To: martinvonz, #hg-reviewers
Cc: mercurial-patches, mercurial-devel

Patch

diff --git a/tests/test-unamend.t b/tests/test-unamend.t
--- a/tests/test-unamend.t
+++ b/tests/test-unamend.t
@@ -6,6 +6,7 @@ 
   > glog = log -G -T '{rev}:{node|short}  {desc}'
   > [experimental]
   > evolution = createmarkers, allowunstable
+  > evolution.allowdivergence = true
   > [extensions]
   > rebase =
   > amend =
diff --git a/tests/test-obsmarker-template.t b/tests/test-obsmarker-template.t
--- a/tests/test-obsmarker-template.t
+++ b/tests/test-obsmarker-template.t
@@ -11,6 +11,7 @@ 
   > publish=False
   > [experimental]
   > evolution=true
+  > evolution.allowdivergence=true
   > [templates]
   > obsfatesuccessors = "{if(successors, " as ")}{join(successors, ", ")}"
   > obsfateverb = "{obsfateverb(successors, markers)}"
diff --git a/tests/test-obshistory.t b/tests/test-obshistory.t
--- a/tests/test-obshistory.t
+++ b/tests/test-obshistory.t
@@ -13,6 +13,7 @@ 
   > [experimental]
   > evolution.createmarkers = yes
   > evolution.effect-flags = yes
+  > evolution.allowdivergence=true
   > EOF
 
 Test output on amended commit
diff --git a/tests/test-branch-change.t b/tests/test-branch-change.t
--- a/tests/test-branch-change.t
+++ b/tests/test-branch-change.t
@@ -150,7 +150,8 @@ 
   [255]
 
   $ hg branch -r 4 --hidden foobar
-  abort: cannot change branch of a obsolete changeset
+  abort: change branch of of 3938acfb5c0f creates content-divergence with 7c1991464886
+  (add --verbose for details)
   [10]
 
 Make sure bookmark movement is correct
diff --git a/tests/test-amend.t b/tests/test-amend.t
--- a/tests/test-amend.t
+++ b/tests/test-amend.t
@@ -232,6 +232,17 @@ 
   $ hg debugobsolete -r .
   112478962961147124edd43549aedd1a335e44bf be169c7e8dbe21cd10b3d79691cbe7f241e3c21c 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '8', 'operation': 'amend', 'user': 'test'}
   be169c7e8dbe21cd10b3d79691cbe7f241e3c21c 16084da537dd8f84cfdb3055c633772269d62e1b 0 (Thu Jan 01 00:00:00 1970 +0000) {'ef1': '8', 'note': 'adding bar', 'operation': 'amend', 'user': 'test'}
+
+Cannot cause divergence by default
+
+  $ hg co --hidden 1
+  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ hg amend -m divergent
+  abort: amend of 112478962961 creates content-divergence with 16084da537dd
+  (add --verbose for details)
+  [10]
+  $ hg amend -m divergent --config experimental.evolution.allowdivergence=true
+  2 new content-divergent changesets
 #endif
 
 Cannot amend public changeset
diff --git a/mercurial/rewriteutil.py b/mercurial/rewriteutil.py
--- a/mercurial/rewriteutil.py
+++ b/mercurial/rewriteutil.py
@@ -59,6 +59,36 @@ 
             _(b"cannot %s changeset with children") % action, hint=hint
         )
 
+    if not obsolete.isenabled(repo, obsolete.allowdivergenceopt):
+        new_divergence = _find_new_divergence(repo, revs)
+        if new_divergence:
+            local_ctx, other_ctx, base_ctx = new_divergence
+            msg = _(b'%s of %s creates content-divergence with %s') % (
+                action,
+                local_ctx,
+                other_ctx,
+            )
+            if local_ctx.rev() != base_ctx.rev():
+                msg += _(b', from %s') % base_ctx
+            if repo.ui.verbose:
+                if local_ctx.rev() != base_ctx.rev():
+                    msg += _(
+                        b'\n    changeset %s is a successor of ' b'changeset %s'
+                    ) % (local_ctx, base_ctx)
+                msg += _(
+                    b'\n    changeset %s already has a successor in '
+                    b'changeset %s\n'
+                    b'    rewriting changeset %s would create '
+                    b'"content-divergence"\n'
+                    b'    set experimental.evolution.allowdivergence=True to '
+                    b'skip this check'
+                ) % (base_ctx, other_ctx, local_ctx)
+                raise error.InputError(msg)
+            else:
+                raise error.InputError(
+                    msg, hint=_(b"add --verbose for details")
+                )
+
 
 def disallowednewunstable(repo, revs):
     """Checks whether editing the revs will create new unstable changesets and
@@ -73,6 +103,40 @@ 
     return repo.revs(b"(%ld::) - %ld", revs, revs)
 
 
+def _find_new_divergence(repo, revs):
+    obsrevs = repo.revs(b'%ld and obsolete()', revs)
+    for r in obsrevs:
+        div = find_new_divergence_from(repo, repo[r])
+        if div:
+            return (repo[r], repo[div[0]], repo[div[1]])
+    return None
+
+
+def find_new_divergence_from(repo, ctx):
+    """return divergent revision if rewriting an obsolete cset (ctx) will
+    create divergence
+
+    Returns (<other node>, <common ancestor node>) or None
+    """
+    if not ctx.obsolete():
+        return None
+    # We need to check two cases that can cause divergence:
+    # case 1: the rev being rewritten has a non-obsolete successor (easily
+    #     detected by successorssets)
+    sset = obsutil.successorssets(repo, ctx.node())
+    if sset:
+        return (sset[0][0], ctx.node())
+    else:
+        # case 2: one of the precursors of the rev being revived has a
+        #     non-obsolete successor (we need divergentsets for this)
+        divsets = obsutil.divergentsets(repo, ctx)
+        if divsets:
+            nsuccset = divsets[0][b'divergentnodes']
+            prec = divsets[0][b'commonpredecessor']
+            return (nsuccset[0], prec)
+        return None
+
+
 def skip_empty_successor(ui, command):
     empty_successor = ui.config(b'rewrite', b'empty-successor')
     if empty_successor == b'skip':
diff --git a/mercurial/obsolete.py b/mercurial/obsolete.py
--- a/mercurial/obsolete.py
+++ b/mercurial/obsolete.py
@@ -103,6 +103,7 @@ 
 # Options for obsolescence
 createmarkersopt = b'createmarkers'
 allowunstableopt = b'allowunstable'
+allowdivergenceopt = b'allowdivergence'
 exchangeopt = b'exchange'
 
 
@@ -141,10 +142,13 @@ 
 
     createmarkersvalue = _getoptionvalue(repo, createmarkersopt)
     unstablevalue = _getoptionvalue(repo, allowunstableopt)
+    divergencevalue = _getoptionvalue(repo, allowdivergenceopt)
     exchangevalue = _getoptionvalue(repo, exchangeopt)
 
     # createmarkers must be enabled if other options are enabled
-    if (unstablevalue or exchangevalue) and not createmarkersvalue:
+    if (
+        unstablevalue or divergencevalue or exchangevalue
+    ) and not createmarkersvalue:
         raise error.Abort(
             _(
                 b"'createmarkers' obsolete option must be enabled "
@@ -155,6 +159,7 @@ 
     return {
         createmarkersopt: createmarkersvalue,
         allowunstableopt: unstablevalue,
+        allowdivergenceopt: divergencevalue,
         exchangeopt: exchangevalue,
     }
 
diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -446,8 +446,15 @@ 
             rebaseset = set(destmap.keys())
             rebaseset -= set(self.obsolete_with_successor_in_destination)
             rebaseset -= self.obsolete_with_successor_in_rebase_set
+            # We have our own divergence-checking in the rebase extension
+            overrides = {}
+            if obsolete.isenabled(self.repo, obsolete.createmarkersopt):
+                overrides = {
+                    (b'experimental', b'evolution.allowdivergence'): b'true'
+                }
             try:
-                rewriteutil.precheck(self.repo, rebaseset, action=b'rebase')
+                with self.ui.configoverride(overrides):
+                    rewriteutil.precheck(self.repo, rebaseset, action=b'rebase')
             except error.Abort as e:
                 if e.hint is None:
                     e.hint = _(b'use --keep to keep original changesets')