tests/test-merge-commit.t

files: speed up `hg files` when no flags change display

It's not the first time I see slowness from this command slow down
tools built on top of hg.

The majority of the time is spent merely printing the result before
this change, which is clearly not how it should be (especially since
the computation of the result also looks slow).

Running `hg files` in mozilla-central:

parent revision: 1,260s
this commit: 0,683s
this commit without batching ui.write: 0,931s
this commit replacing the body of the loop with `pass`: 0,566s

This looks like a prime candidate for a rust fast path, but until
then, it seems reasonable to optimize the python.

Differential Revision: https://phab.mercurial-scm.org/D8586

Check that renames are correctly saved by a commit after a merge

Test with the merge on 3 having the rename on the local parent

  $ hg init a
  $ cd a

  $ echo line1 > foo
  $ hg add foo
  $ hg ci -m '0: add foo'

  $ echo line2 >> foo
  $ hg ci -m '1: change foo'

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg mv foo bar
  $ rm bar
  $ echo line0 > bar
  $ echo line1 >> bar
  $ hg ci -m '2: mv foo bar; change bar'
  created new head

  $ hg merge 1
  merging bar and foo to bar
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat bar
  line0
  line1
  line2

  $ hg ci -m '3: merge with local rename'

  $ hg debugindex bar
     rev linkrev nodeid       p1           p2
       0       2 d35118874825 000000000000 000000000000
       1       3 5345f5ab8abd 000000000000 d35118874825

  $ hg debugrename bar
  bar renamed from foo:9e25c27b87571a1edee5ae4dddee5687746cc8e2

  $ hg debugindex foo
     rev linkrev nodeid       p1           p2
       0       0 690b295714ae 000000000000 000000000000
       1       1 9e25c27b8757 690b295714ae 000000000000


Revert the content change from rev 2:

  $ hg up -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm bar
  $ echo line1 > bar
  $ hg ci -m '4: revert content change from rev 2'
  created new head

  $ hg log --template '{rev}:{node|short} {parents}\n'
  4:2263c1be0967 2:0f2ff26688b9 
  3:0555950ead28 2:0f2ff26688b9 1:5cd961e4045d 
  2:0f2ff26688b9 0:2665aaee66e9 
  1:5cd961e4045d 
  0:2665aaee66e9 

This should use bar@rev2 as the ancestor:

  $ hg --debug merge 3
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 0f2ff26688b9, local: 2263c1be0967+, remote: 0555950ead28
   preserving bar for resolve of bar
  starting 4 threads for background file closing (?)
   bar: versions differ -> m (premerge)
  picked tool ':merge' for bar (binary False symlink False changedelete False)
  merging bar
  my bar@2263c1be0967+ other bar@0555950ead28 ancestor bar@0f2ff26688b9
   premerge successful
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat bar
  line1
  line2

  $ hg ci -m '5: merge'

  $ hg debugindex bar
     rev linkrev nodeid       p1           p2
       0       2 d35118874825 000000000000 000000000000
       1       3 5345f5ab8abd 000000000000 d35118874825
       2       4 ff4b45017382 d35118874825 000000000000
       3       5 3701b4893544 ff4b45017382 5345f5ab8abd


Same thing, but with the merge on 3 having the rename
on the remote parent:

  $ cd ..
  $ hg clone -U -r 1 -r 2 a b
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 2 files (+1 heads)
  new changesets 2665aaee66e9:0f2ff26688b9
  $ cd b

  $ hg up -C 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg merge 2
  merging foo and bar to bar
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat bar
  line0
  line1
  line2

  $ hg ci -m '3: merge with remote rename'

  $ hg debugindex bar
     rev linkrev nodeid       p1           p2
       0       2 d35118874825 000000000000 000000000000
       1       3 5345f5ab8abd 000000000000 d35118874825

  $ hg debugrename bar
  bar renamed from foo:9e25c27b87571a1edee5ae4dddee5687746cc8e2

  $ hg debugindex foo
     rev linkrev nodeid       p1           p2
       0       0 690b295714ae 000000000000 000000000000
       1       1 9e25c27b8757 690b295714ae 000000000000


Revert the content change from rev 2:

  $ hg up -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm bar
  $ echo line1 > bar
  $ hg ci -m '4: revert content change from rev 2'
  created new head

  $ hg log --template '{rev}:{node|short} {parents}\n'
  4:2263c1be0967 2:0f2ff26688b9 
  3:3ffa6b9e35f0 1:5cd961e4045d 2:0f2ff26688b9 
  2:0f2ff26688b9 0:2665aaee66e9 
  1:5cd961e4045d 
  0:2665aaee66e9 

This should use bar@rev2 as the ancestor:

  $ hg --debug merge 3
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 0f2ff26688b9, local: 2263c1be0967+, remote: 3ffa6b9e35f0
   preserving bar for resolve of bar
  starting 4 threads for background file closing (?)
   bar: versions differ -> m (premerge)
  picked tool ':merge' for bar (binary False symlink False changedelete False)
  merging bar
  my bar@2263c1be0967+ other bar@3ffa6b9e35f0 ancestor bar@0f2ff26688b9
   premerge successful
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat bar
  line1
  line2

  $ hg ci -m '5: merge'

  $ hg debugindex bar
     rev linkrev nodeid       p1           p2
       0       2 d35118874825 000000000000 000000000000
       1       3 5345f5ab8abd 000000000000 d35118874825
       2       4 ff4b45017382 d35118874825 000000000000
       3       5 3701b4893544 ff4b45017382 5345f5ab8abd

  $ cd ..