tests/test-copies.t

changelog: optionally store added and removed files in changeset extras

As mentioned in an earlier patch, copies._chain() is used a lot in the
changeset-centric version of pathcopies(). It is expensive because it
needs to look at the manifest in order to filter out copies whose
target file has since been removed. I want to store the sets of added
and removed files in the changeset in order to speed that up. This
patch does the writing part of that. It could easily be a separate
config, but it's currently tied to experimental.copies.write-to since
that's the only real use case (it will also make the {file_*} template
keywords faster, but I doubt that anyone cares enough about those to
write extra metadata for them).

The new information is stored in the changeset extras. Since they're
always subsets of the changeset's "files" list, they're stored as
indexes into that list. I've stored the indexes as stringified ints
separated by NUL bytes. The size of 00changelog.d for the hg repo
increased in size by 0.28% percent (compared to the size with only
copy information in the changesets, which in turn is 0.17% larger than
without copy information). We could store only the delta between the
indexes and we could store them in binary, but the chosen format is
more readable.

We could also have implemented this as a cache outside the
changelog. One advantage of doing it that way is that we would get the
speedups from the {file_*} template keywords also on old
repos. Another advantage is that it we can rewrite the cache if we
find a bug in how we calculate the set of files. A disadvantage is
that it would be more complex. Another is that it would surely use
more space. We already write the copy information to the changeset
extras, so it seems like a small step to also write these file sets.

Differential Revision: https://phab.mercurial-scm.org/D6416

#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.
  $ 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
  $ hg debugpathcopies 2 4
  $ hg debugpathcopies 0 4
  x -> z (filelog !)
  y -> z (compatibility !)
  $ hg debugpathcopies 1 5
  $ hg debugpathcopies 2 5
  $ 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 df722b7fe2d5 -r ba3ddbbdfd96 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 5:619047c26bf8 "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 6:9ddc6fb3b691 "added willconflict and d" (tip) (changeset !)