tests/test-copies.t

copies: don't filter out copy targets created on other side of merge commit

If file X is copied to Y on one side of merge and the other side
creates Y (no copy), we would not mark that as copy. In the
changeset-centric pathcopies() version, that was done by checking if
the copy target existed on the other branch. Even though merge commits
are pretty uncommon, it still turned out to be too expensive to load
the manifest of the parents of merge commits. In a repo of
mozilla-unified converted to storing copies in changesets, about 2m30s
of `hg debugpathcopies FIREFOX_BETA_59_END FIREFOX_BETA_60_BASE` is
spent on this check of merge commits.

I tried to think of a way of storing more information in the
changesets in order to cheaply detect these cases, but I couldn't
think of a solution. So this patch simply removes those checks.

For reference, these extra copies are reported from the aforementioned
command after this patch:

  browser/base/content/sanitize.js -> browser/modules/Sanitizer.jsm
  testing/mozbase/mozprocess/tests/process_normal_finish_python.ini -> testing/mozbase/mozprocess/tests/process_normal_finish.ini
  testing/mozbase/mozprocess/tests/process_waittimeout_python.ini -> testing/mozbase/mozprocess/tests/process_waittimeout.ini
  testing/mozbase/mozprocess/tests/process_waittimeout_10s_python.ini -> testing/mozbase/mozprocess/tests/process_waittimeout_10s.ini

Since these copies were created on one side of some merge, it still
seems reasonable to include them, so I'm not even sure it's worse than
filelog pathcopies(), just different.

Differential Revision: https://phab.mercurial-scm.org/D6420

#testcases filelog compatibility changeset

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > rebase=
  > [alias]
  > l = log -G -T '{rev} {desc}\n{files}\n'
  > EOF

#if compatibility
  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > copies.read-from = compatibility
  > EOF
#endif

#if changeset
  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > copies.read-from = changeset-only
  > copies.write-to = changeset-only
  > EOF
#endif

  $ REPONUM=0
  $ newrepo() {
  >     cd $TESTTMP
  >     REPONUM=`expr $REPONUM + 1`
  >     hg init repo-$REPONUM
  >     cd repo-$REPONUM
  > }

Simple rename case
  $ newrepo
  $ echo x > x
  $ hg ci -Aqm 'add x'
  $ hg mv x y
  $ hg debugp1copies
  x -> y
  $ hg debugp2copies
  $ hg ci -m 'rename x to y'
  $ hg l
  @  1 rename x to y
  |  x y
  o  0 add x
     x
  $ hg debugp1copies -r 1
  x -> y
  $ hg debugpathcopies 0 1
  x -> y
  $ hg debugpathcopies 1 0
  y -> x
Test filtering copies by path. We do filtering by destination.
  $ hg debugpathcopies 0 1 x
  $ hg debugpathcopies 1 0 x
  y -> x
  $ hg debugpathcopies 0 1 y
  x -> y
  $ hg debugpathcopies 1 0 y

Copy a file onto another file
  $ newrepo
  $ echo x > x
  $ echo y > y
  $ hg ci -Aqm 'add x and y'
  $ hg cp -f x y
  $ hg debugp1copies
  x -> y
  $ hg debugp2copies
  $ hg ci -m 'copy x onto y'
  $ hg l
  @  1 copy x onto y
  |  y
  o  0 add x and y
     x y
  $ hg debugp1copies -r 1
  x -> y
Incorrectly doesn't show the rename
  $ hg debugpathcopies 0 1

Copy a file onto another file with same content. If metadata is stored in changeset, this does not
produce a new filelog entry. The changeset's "files" entry should still list the file.
  $ newrepo
  $ echo x > x
  $ echo x > x2
  $ hg ci -Aqm 'add x and x2 with same content'
  $ hg cp -f x x2
  $ hg ci -m 'copy x onto x2'
  $ hg l
  @  1 copy x onto x2
  |  x2
  o  0 add x and x2 with same content
     x x2
  $ hg debugp1copies -r 1
  x -> x2
Incorrectly doesn't show the rename
  $ hg debugpathcopies 0 1

Copy a file, then delete destination, then copy again. This does not create a new filelog entry.
  $ newrepo
  $ echo x > x
  $ hg ci -Aqm 'add x'
  $ hg cp x y
  $ hg ci -m 'copy x to y'
  $ hg rm y
  $ hg ci -m 'remove y'
  $ hg cp -f x y
  $ hg ci -m 'copy x onto y (again)'
  $ hg l
  @  3 copy x onto y (again)
  |  y
  o  2 remove y
  |  y
  o  1 copy x to y
  |  y
  o  0 add x
     x
  $ hg debugp1copies -r 3
  x -> y
  $ hg debugpathcopies 0 3
  x -> y

Rename file in a loop: x->y->z->x
  $ newrepo
  $ echo x > x
  $ hg ci -Aqm 'add x'
  $ hg mv x y
  $ hg debugp1copies
  x -> y
  $ hg debugp2copies
  $ hg ci -m 'rename x to y'
  $ hg mv y z
  $ hg ci -m 'rename y to z'
  $ hg mv z x
  $ hg ci -m 'rename z to x'
  $ hg l
  @  3 rename z to x
  |  x z
  o  2 rename y to z
  |  y z
  o  1 rename x to y
  |  x y
  o  0 add x
     x
  $ hg debugpathcopies 0 3

Copy x to y, then remove y, then add back y. With copy metadata in the changeset, this could easily
end up reporting y as copied from x (if we don't unmark it as a copy when it's removed).
  $ newrepo
  $ echo x > x
  $ hg ci -Aqm 'add x'
  $ hg mv x y
  $ hg ci -m 'rename x to y'
  $ hg rm y
  $ hg ci -qm 'remove y'
  $ echo x > y
  $ hg ci -Aqm 'add back y'
  $ hg l
  @  3 add back y
  |  y
  o  2 remove y
  |  y
  o  1 rename x to y
  |  x y
  o  0 add x
     x
  $ hg debugp1copies -r 3
  $ hg debugpathcopies 0 3

Copy x to z, then remove z, then copy x2 (same content as x) to z. With copy metadata in the
changeset, the two copies here will have the same filelog entry, so ctx['z'].introrev() might point
to the first commit that added the file. We should still report the copy as being from x2.
  $ newrepo
  $ echo x > x
  $ echo x > x2
  $ hg ci -Aqm 'add x and x2 with same content'
  $ hg cp x z
  $ hg ci -qm 'copy x to z'
  $ hg rm z
  $ hg ci -m 'remove z'
  $ hg cp x2 z
  $ hg ci -m 'copy x2 to z'
  $ hg l
  @  3 copy x2 to z
  |  z
  o  2 remove z
  |  z
  o  1 copy x to z
  |  z
  o  0 add x and x2 with same content
     x x2
  $ hg debugp1copies -r 3
  x2 -> z
  $ hg debugpathcopies 0 3
  x2 -> z

Create x and y, then rename them both to the same name, but on different sides of a fork
  $ newrepo
  $ echo x > x
  $ echo y > y
  $ hg ci -Aqm 'add x and y'
  $ hg mv x z
  $ hg ci -qm 'rename x to z'
  $ hg co -q 0
  $ hg mv y z
  $ hg ci -qm 'rename y to z'
  $ hg l
  @  2 rename y to z
  |  y z
  | o  1 rename x to z
  |/   x z
  o  0 add x and y
     x y
  $ hg debugpathcopies 1 2
  z -> x
  y -> z

Fork renames x to y on one side and removes x on the other
  $ newrepo
  $ echo x > x
  $ hg ci -Aqm 'add x'
  $ hg mv x y
  $ hg ci -m 'rename x to y'
  $ hg co -q 0
  $ hg rm x
  $ hg ci -m 'remove x'
  created new head
  $ hg l
  @  2 remove x
  |  x
  | o  1 rename x to y
  |/   x y
  o  0 add x
     x
  $ hg debugpathcopies 1 2

Copies via null revision (there shouldn't be any)
  $ newrepo
  $ echo x > x
  $ hg ci -Aqm 'add x'
  $ hg cp x y
  $ hg ci -m 'copy x to y'
  $ hg co -q null
  $ echo x > x
  $ hg ci -Aqm 'add x (again)'
  $ hg l
  @  2 add x (again)
     x
  o  1 copy x to y
  |  y
  o  0 add x
     x
  $ hg debugpathcopies 1 2
  $ hg debugpathcopies 2 1

Merge rename from other branch
  $ newrepo
  $ echo x > x
  $ hg ci -Aqm 'add x'
  $ hg mv x y
  $ hg ci -m 'rename x to y'
  $ hg co -q 0
  $ echo z > z
  $ hg ci -Aqm 'add z'
  $ hg merge -q 1
  $ hg debugp1copies
  $ hg debugp2copies
  $ hg ci -m 'merge rename from p2'
  $ hg l
  @    3 merge rename from p2
  |\   x
  | o  2 add z
  | |  z
  o |  1 rename x to y
  |/   x y
  o  0 add x
     x
Perhaps we should indicate the rename here, but `hg status` is documented to be weird during
merges, so...
  $ hg debugp1copies -r 3
  $ hg debugp2copies -r 3
  $ hg debugpathcopies 0 3
  x -> y
  $ hg debugpathcopies 1 2
  y -> x
  $ hg debugpathcopies 1 3
  $ hg debugpathcopies 2 3
  x -> y

Copy file from either side in a merge
  $ newrepo
  $ echo x > x
  $ hg ci -Aqm 'add x'
  $ hg co -q null
  $ echo y > y
  $ hg ci -Aqm 'add y'
  $ hg merge -q 0
  $ hg cp y z
  $ hg debugp1copies
  y -> z
  $ hg debugp2copies
  $ hg ci -m 'copy file from p1 in merge'
  $ hg co -q 1
  $ hg merge -q 0
  $ hg cp x z
  $ hg debugp1copies
  $ hg debugp2copies
  x -> z
  $ hg ci -qm 'copy file from p2 in merge'
  $ hg l
  @    3 copy file from p2 in merge
  |\   z
  +---o  2 copy file from p1 in merge
  | |/   z
  | o  1 add y
  |    y
  o  0 add x
     x
  $ hg debugp1copies -r 2
  y -> z
  $ hg debugp2copies -r 2
  $ hg debugpathcopies 1 2
  y -> z
  $ hg debugpathcopies 0 2
  $ hg debugp1copies -r 3
  $ hg debugp2copies -r 3
  x -> z
  $ hg debugpathcopies 1 3
  $ hg debugpathcopies 0 3
  x -> z

Copy file that exists on both sides of the merge, same content on both sides
  $ newrepo
  $ echo x > x
  $ hg ci -Aqm 'add x on branch 1'
  $ hg co -q null
  $ echo x > x
  $ hg ci -Aqm 'add x on branch 2'
  $ hg merge -q 0
  $ hg cp x z
  $ hg debugp1copies
  x -> z
  $ hg debugp2copies
  $ hg ci -qm 'merge'
  $ hg l
  @    2 merge
  |\   z
  | o  1 add x on branch 2
  |    x
  o  0 add x on branch 1
     x
  $ hg debugp1copies -r 2
  x -> z
  $ hg debugp2copies -r 2
It's a little weird that it shows up on both sides
  $ hg debugpathcopies 1 2
  x -> z
  $ hg debugpathcopies 0 2
  x -> z (filelog !)

Copy file that exists on both sides of the merge, different content
  $ newrepo
  $ echo branch1 > x
  $ hg ci -Aqm 'add x on branch 1'
  $ hg co -q null
  $ echo branch2 > x
  $ hg ci -Aqm 'add x on branch 2'
  $ hg merge -q 0
  warning: conflicts while merging x! (edit, then use 'hg resolve --mark')
  [1]
  $ echo resolved > x
  $ hg resolve -m x
  (no more unresolved files)
  $ hg cp x z
  $ hg debugp1copies
  x -> z
  $ hg debugp2copies
  $ hg ci -qm 'merge'
  $ hg l
  @    2 merge
  |\   x z
  | o  1 add x on branch 2
  |    x
  o  0 add x on branch 1
     x
  $ hg debugp1copies -r 2
  x -> z (changeset !)
  $ hg debugp2copies -r 2
  x -> z (no-changeset !)
  $ hg debugpathcopies 1 2
  x -> z (changeset !)
  $ hg debugpathcopies 0 2
  x -> z (no-changeset !)

Copy x->y on one side of merge and copy x->z on the other side. Pathcopies from one parent
of the merge to the merge should include the copy from the other side.
  $ newrepo
  $ echo x > x
  $ hg ci -Aqm 'add x'
  $ hg cp x y
  $ hg ci -qm 'copy x to y'
  $ hg co -q 0
  $ hg cp x z
  $ hg ci -qm 'copy x to z'
  $ hg merge -q 1
  $ hg ci -m 'merge copy x->y and copy x->z'
  $ hg l
  @    3 merge copy x->y and copy x->z
  |\
  | o  2 copy x to z
  | |  z
  o |  1 copy x to y
  |/   y
  o  0 add x
     x
  $ hg debugp1copies -r 3
  $ hg debugp2copies -r 3
  $ hg debugpathcopies 2 3
  x -> y
  $ hg debugpathcopies 1 3
  x -> z

Copy x to y on one side of merge, create y and rename to z on the other side. Pathcopies from the
first side should not include the y->z rename since y didn't exist in the merge base.
  $ newrepo
  $ echo x > x
  $ hg ci -Aqm 'add x'
  $ hg cp x y
  $ hg ci -qm 'copy x to y'
  $ hg co -q 0
  $ echo y > y
  $ hg ci -Aqm 'add y'
  $ hg mv y z
  $ hg ci -m 'rename y to z'
  $ hg merge -q 1
  $ hg ci -m 'merge'
  $ hg l
  @    4 merge
  |\
  | o  3 rename y to z
  | |  y z
  | o  2 add y
  | |  y
  o |  1 copy x to y
  |/   y
  o  0 add x
     x
  $ hg debugp1copies -r 3
  y -> z
  $ hg debugp2copies -r 3
  $ hg debugpathcopies 2 3
  y -> z
  $ hg debugpathcopies 1 3

Create x and y, then rename x to z on one side of merge, and rename y to z and
modify z on the other side. When storing copies in the changeset, we don't
filter out copies whose target was created on the other side of the merge.
  $ newrepo
  $ echo x > x
  $ echo y > y
  $ hg ci -Aqm 'add x and y'
  $ hg mv x z
  $ hg ci -qm 'rename x to z'
  $ hg co -q 0
  $ hg mv y z
  $ hg ci -qm 'rename y to z'
  $ echo z >> z
  $ hg ci -m 'modify z'
  $ hg merge -q 1
  warning: conflicts while merging z! (edit, then use 'hg resolve --mark')
  [1]
  $ echo z > z
  $ hg resolve -qm z
  $ hg ci -m 'merge 1 into 3'
Try merging the other direction too
  $ hg co -q 1
  $ hg merge -q 3
  warning: conflicts while merging z! (edit, then use 'hg resolve --mark')
  [1]
  $ echo z > z
  $ hg resolve -qm z
  $ hg ci -m 'merge 3 into 1'
  created new head
  $ hg l
  @    5 merge 3 into 1
  |\   y z
  +---o  4 merge 1 into 3
  | |/   x z
  | o  3 modify z
  | |  z
  | o  2 rename y to z
  | |  y z
  o |  1 rename x to z
  |/   x z
  o  0 add x and y
     x y
  $ hg debugpathcopies 1 4
  y -> z (no-filelog !)
  $ hg debugpathcopies 2 4
  x -> z (no-filelog !)
  $ hg debugpathcopies 0 4
  x -> z (filelog !)
  y -> z (compatibility !)
  $ hg debugpathcopies 1 5
  y -> z (no-filelog !)
  $ hg debugpathcopies 2 5
  x -> z (no-filelog !)
  $ hg debugpathcopies 0 5
  x -> z


Test for a case in fullcopytracing algorithm where neither of the merging csets
is a descendant of the merge base. This test reflects that the algorithm
correctly finds the copies:

  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > evolution.createmarkers=True
  > evolution.allowunstable=True
  > EOF

  $ newrepo
  $ echo a > a
  $ hg add a
  $ hg ci -m "added a"
  $ echo b > b
  $ hg add b
  $ hg ci -m "added b"

  $ hg mv b b1
  $ hg ci -m "rename b to b1"

  $ hg up ".^"
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo d > d
  $ hg add d
  $ hg ci -m "added d"
  created new head

  $ echo baba >> b
  $ hg ci --amend -m "added d, modified b"

  $ hg l --hidden
  @  4 added d, modified b
  |  b d
  | x  3 added d
  |/   d
  | o  2 rename b to b1
  |/   b b1
  o  1 added b
  |  b
  o  0 added a
     a

Grafting revision 4 on top of revision 2, showing that it respect the rename:

  $ hg up 2 -q
  $ hg graft -r 4 --base 3 --hidden
  grafting 4:af28412ec03c "added d, modified b" (tip) (no-changeset !)
  grafting 4:6325ca0b7a1c "added d, modified b" (tip) (changeset !)
  merging b1 and b to b1

  $ hg l -l1 -p
  @  5 added d, modified b
  |  b1
  ~  diff -r 5a4825cc2926 -r 94a2f1a0e8e2 b1 (no-changeset !)
  ~  diff -r 0a0ed3b3251c -r d544fb655520 b1 (changeset !)
     --- a/b1	Thu Jan 01 00:00:00 1970 +0000
     +++ b/b1	Thu Jan 01 00:00:00 1970 +0000
     @@ -1,1 +1,2 @@
      b
     +baba
  
Test to make sure that fullcopytracing algorithm doesn't fail when neither of the
merging csets is a descendant of the base.
-------------------------------------------------------------------------------------------------

  $ newrepo
  $ echo a > a
  $ hg add a
  $ hg ci -m "added a"
  $ echo b > b
  $ hg add b
  $ hg ci -m "added b"

  $ echo foobar > willconflict
  $ hg add willconflict
  $ hg ci -m "added willconflict"
  $ echo c > c
  $ hg add c
  $ hg ci -m "added c"

  $ hg l
  @  3 added c
  |  c
  o  2 added willconflict
  |  willconflict
  o  1 added b
  |  b
  o  0 added a
     a

  $ hg up ".^^"
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ echo d > d
  $ hg add d
  $ hg ci -m "added d"
  created new head

  $ echo barfoo > willconflict
  $ hg add willconflict
  $ hg ci --amend -m "added willconflict and d"

  $ hg l
  @  5 added willconflict and d
  |  d willconflict
  | o  3 added c
  | |  c
  | o  2 added willconflict
  |/   willconflict
  o  1 added b
  |  b
  o  0 added a
     a

  $ hg rebase -r . -d 2 -t :other
  rebasing 5:5018b1509e94 "added willconflict and d" (tip) (no-changeset !)
  rebasing 5:af8d273bf580 "added willconflict and d" (tip) (changeset !)

  $ hg up 3 -q
  $ hg l --hidden
  o  6 added willconflict and d
  |  d willconflict
  | x  5 added willconflict and d
  | |  d willconflict
  | | x  4 added d
  | |/   d
  +---@  3 added c
  | |    c
  o |  2 added willconflict
  |/   willconflict
  o  1 added b
  |  b
  o  0 added a
     a

Now if we trigger a merge between revision 3 and 6 using base revision 4,
neither of the merging csets will be a descendant of the base revision:

  $ hg graft -r 6 --base 4 --hidden -t :other
  grafting 6:99802e4f1e46 "added willconflict and d" (tip) (no-changeset !)
  grafting 6:b19f0df72728 "added willconflict and d" (tip) (changeset !)