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Differential D10120

copies: filter out copies grafted from another branch
ClosedPublic

Authored by martinvonz on Mar 5 2021, 7:41 PM.

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Commits
rHG2803f94b7431: copies: filter out copies grafted from another branch
Summary

Consider this simple history:

@  3 modify y
|
o  2 copy x to y, modify x
|
| o  1 copy x to y, modify x
|/
o  0 add x

If we now rebase commit 3 onto 1, Mercurial will look for copies
between commit 2 and commit 1. It does that by going backwards from 2
to 0 and then forwards from 0 to 1. It will find that x was copied to
y, since that was what happened on the path between them (namely in
commit 1). That leads Mercurial to do a 3-way merge between y@3 and
y@1 with x@2 as base. We want to use y@2 as base instead. That's also
what happened until commit 1d6d1a15. This patch fixes the regression
by adding another filtering step when chaining copies via a
diffbase. The new filtering step removes copies that were the same
between the two branches (same source and destination, but not
necessarily the same contents).

Diff Detail

Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Revision Contents
Changeset List

PathPackages
Mmercurial/copies.py (5 lines)
Mtests/test-copies.t (3 lines)
Mtests/test-graft.t (8 lines)

Diff 26139

mercurial/copies.py

else: else:
if debug: if debug:
repo.ui.debug(b'debug.copies: search mode: combined\n') repo.ui.debug(b'debug.copies: search mode: combined\n')
base = None base = None
if a.rev() != nullrev: if a.rev() != nullrev:
base = x base = x
x_copies = _forwardcopies(a, x) x_copies = _forwardcopies(a, x)
y_copies = _forwardcopies(a, y, base, match=match) y_copies = _forwardcopies(a, y, base, match=match)
same_keys = set(x_copies) & set(y_copies)
for k in same_keys:
if x_copies.get(k) == y_copies.get(k):
del x_copies[k]
del y_copies[k]
x_backward_renames = _reverse_renames(x_copies, x, match) x_backward_renames = _reverse_renames(x_copies, x, match)
copies = _chain( copies = _chain(
x_backward_renames, x_backward_renames,
y_copies, y_copies,
) )
_filter(x, y, copies) _filter(x, y, copies)
return copies return copies

tests/test-copies.t

| o 1 copy x to y | o 1 copy x to y
|/ y |/ y
o 0 add x o 0 add x
x x
$ hg debugp1copies -r 1 $ hg debugp1copies -r 1
x -> y x -> y
$ hg debugp1copies -r 2 $ hg debugp1copies -r 2
x -> y x -> y
BROKEN: These two should not report any copies
$ hg debugpathcopies 1 2 $ hg debugpathcopies 1 2
x -> y
$ hg debugpathcopies 2 1 $ hg debugpathcopies 2 1
x -> y
Copy x to y on one side of merge, create y and rename to z on the other side. Copy x to y on one side of merge, create y and rename to z on the other side.
$ newrepo $ newrepo
$ echo x > x $ echo x > x
$ hg ci -Aqm 'add x' $ hg ci -Aqm 'add x'
$ hg cp x y $ hg cp x y
$ hg ci -qm 'copy x to y' $ hg ci -qm 'copy x to y'
$ hg co -q 0 $ hg co -q 0

tests/test-graft.t

my b@ef0ef43d49e7+ other a@5d205f8b35b6 ancestor a@68795b066622 my b@ef0ef43d49e7+ other a@5d205f8b35b6 ancestor a@68795b066622
premerge successful premerge successful
committing files: committing files:
b b
committing manifest committing manifest
committing changelog committing changelog
updating the branch cache updating the branch cache
grafting 5:97f8bfe72746 "5" grafting 5:97f8bfe72746 "5"
all copies found (* = to merge, ! = divergent, % = renamed and deleted):
on local side:
src: 'c' -> dst: 'b'
checking for directory renames
resolving manifests resolving manifests
branchmerge: True, force: True, partial: False branchmerge: True, force: True, partial: False
ancestor: 4c60f11aa304, local: 6b9e5368ca4e+, remote: 97f8bfe72746 ancestor: 4c60f11aa304, local: 6b9e5368ca4e+, remote: 97f8bfe72746
e: remote is newer -> g e: remote is newer -> g
getting e getting e
committing files: committing files:
e e
committing manifest committing manifest
committing changelog committing changelog
updating the branch cache updating the branch cache
$ HGEDITOR=cat hg graft 4 3 --log --debug $ HGEDITOR=cat hg graft 4 3 --log --debug
scanning for duplicate grafts scanning for duplicate grafts
grafting 4:9c233e8e184d "4" grafting 4:9c233e8e184d "4"
all copies found (* = to merge, ! = divergent, % = renamed and deleted):
on local side:
src: 'c' -> dst: 'b'
checking for directory renames
resolving manifests resolving manifests
branchmerge: True, force: True, partial: False branchmerge: True, force: True, partial: False
ancestor: 4c60f11aa304, local: 1905859650ec+, remote: 9c233e8e184d ancestor: 4c60f11aa304, local: 1905859650ec+, remote: 9c233e8e184d
d: remote is newer -> g d: remote is newer -> g
getting d getting d
preserving e for resolve of e preserving e for resolve of e
e: versions differ -> m (premerge) e: versions differ -> m (premerge)
picked tool ':merge' for e (binary False symlink False changedelete False) picked tool ':merge' for e (binary False symlink False changedelete False)