view tests/test-mv-cp-st-diff.t @ 24560:b38bcf18993c

dirstate.walk: don't keep track of normalized files in parallel Rev 2bb13f2b778c changed the semantics of the work list to store (normalized, non-normalized) pairs. All the tuple creation and destruction hurts perf: on a large repo on OS X, 'hg status' went from 3.62 seconds to 3.78. It also is unnecessary in most cases: - it is clearly unnecessary on case-sensitive filesystems. - it is also unnecessary when filenames have been read off of disk rather than being supplied by the user. The only case where the non-normalized case is required at all is when the file is unknown. To eliminate most of the perf cost, keep trace of whether the directory needs to be normalized at all with a boolean called 'alreadynormed'. Pay the cost of directory normalization only when necessary. For the above large repo, 'hg status' goes to 3.63 seconds.
author Siddharth Agarwal <sid0@fb.com>
date Tue, 31 Mar 2015 19:29:39 -0700
parents c48924787eaa
children 4441705b7111
line wrap: on
line source


  $ add()
  > {
  >     echo $2 >> $1
  > }
  $ hg init t
  $ cd t

set up a boring main branch

  $ add a a
  $ hg add a
  $ mkdir x
  $ add x/x x
  $ hg add x/x
  $ hg ci -m0
  $ add a m1
  $ hg ci -m1
  $ add a m2
  $ add x/y y1
  $ hg add x/y
  $ hg ci -m2
  $ cd ..

  $ show()
  > {
  >     echo "# $2:"
  >     echo
  >     echo "% hg st -C $1"
  >     hg st -C $1
  >     echo
  >     echo "% hg diff --git $1"
  >     hg diff --git $1
  >     echo
  > }
  $ count=0

make a new branch and get diff/status output
$1 - first commit
$2 - second commit
$3 - working dir action

  $ tb()
  > {
  >     hg clone -q t t2 ; cd t2
  >     hg co -q -C 0
  > 
  >     echo % add a $count
  >     add a $count
  >     count=`expr $count + 1`
  >     echo % hg ci -m "t0"
  >     hg ci -m "t0"
  >     echo % $1
  >     $1
  >     echo % hg ci -m "t1"
  >     hg ci -m "t1"
  >     echo % $2
  >     $2
  >     echo % hg ci -m "t2"
  >     hg ci -m "t2"
  >     echo % $3
  >     $3
  >     echo
  >     show "" "working to parent"
  >     show "--rev 0" "working to root"
  >     show "--rev 2" "working to branch"
  >     show "--rev 0 --rev ." "root to parent"
  >     show "--rev . --rev 0" "parent to root"
  >     show "--rev 2 --rev ." "branch to parent"
  >     show "--rev . --rev 2" "parent to branch"
  >     echo
  >     cd ..
  >     rm -rf t2
  > }

rename in working dir

  $ tb "add a a1" "add a a2" "hg mv a b"
  % add a 0
  % hg ci -m t0
  created new head
  % add a a1
  % hg ci -m t1
  % add a a2
  % hg ci -m t2
  % hg mv a b
  
  # working to parent:
  
  % hg st -C 
  A b
    a
  R a
  
  % hg diff --git 
  diff --git a/a b/b
  rename from a
  rename to b
  
  # working to root:
  
  % hg st -C --rev 0
  A b
    a
  R a
  
  % hg diff --git --rev 0
  diff --git a/a b/b
  rename from a
  rename to b
  --- a/a
  +++ b/b
  @@ -1,1 +1,4 @@
   a
  +0
  +a1
  +a2
  
  # working to branch:
  
  % hg st -C --rev 2
  A b
    a
  R a
  R x/y
  
  % hg diff --git --rev 2
  diff --git a/a b/b
  rename from a
  rename to b
  --- a/a
  +++ b/b
  @@ -1,3 +1,4 @@
   a
  -m1
  -m2
  +0
  +a1
  +a2
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # root to parent:
  
  % hg st -C --rev 0 --rev .
  M a
  
  % hg diff --git --rev 0 --rev .
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,4 @@
   a
  +0
  +a1
  +a2
  
  # parent to root:
  
  % hg st -C --rev . --rev 0
  M a
  
  % hg diff --git --rev . --rev 0
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,4 +1,1 @@
   a
  -0
  -a1
  -a2
  
  # branch to parent:
  
  % hg st -C --rev 2 --rev .
  M a
  R x/y
  
  % hg diff --git --rev 2 --rev .
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,3 +1,4 @@
   a
  -m1
  -m2
  +0
  +a1
  +a2
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # parent to branch:
  
  % hg st -C --rev . --rev 2
  M a
  A x/y
  
  % hg diff --git --rev . --rev 2
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,4 +1,3 @@
   a
  -0
  -a1
  -a2
  +m1
  +m2
  diff --git a/x/y b/x/y
  new file mode 100644
  --- /dev/null
  +++ b/x/y
  @@ -0,0 +1,1 @@
  +y1
  
  
copy in working dir

  $ tb "add a a1" "add a a2" "hg cp a b"
  % add a 1
  % hg ci -m t0
  created new head
  % add a a1
  % hg ci -m t1
  % add a a2
  % hg ci -m t2
  % hg cp a b
  
  # working to parent:
  
  % hg st -C 
  A b
    a
  
  % hg diff --git 
  diff --git a/a b/b
  copy from a
  copy to b
  
  # working to root:
  
  % hg st -C --rev 0
  M a
  A b
    a
  
  % hg diff --git --rev 0
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,4 @@
   a
  +1
  +a1
  +a2
  diff --git a/a b/b
  copy from a
  copy to b
  --- a/a
  +++ b/b
  @@ -1,1 +1,4 @@
   a
  +1
  +a1
  +a2
  
  # working to branch:
  
  % hg st -C --rev 2
  M a
  A b
    a
  R x/y
  
  % hg diff --git --rev 2
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,3 +1,4 @@
   a
  -m1
  -m2
  +1
  +a1
  +a2
  diff --git a/a b/b
  copy from a
  copy to b
  --- a/a
  +++ b/b
  @@ -1,3 +1,4 @@
   a
  -m1
  -m2
  +1
  +a1
  +a2
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # root to parent:
  
  % hg st -C --rev 0 --rev .
  M a
  
  % hg diff --git --rev 0 --rev .
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,4 @@
   a
  +1
  +a1
  +a2
  
  # parent to root:
  
  % hg st -C --rev . --rev 0
  M a
  
  % hg diff --git --rev . --rev 0
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,4 +1,1 @@
   a
  -1
  -a1
  -a2
  
  # branch to parent:
  
  % hg st -C --rev 2 --rev .
  M a
  R x/y
  
  % hg diff --git --rev 2 --rev .
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,3 +1,4 @@
   a
  -m1
  -m2
  +1
  +a1
  +a2
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # parent to branch:
  
  % hg st -C --rev . --rev 2
  M a
  A x/y
  
  % hg diff --git --rev . --rev 2
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,4 +1,3 @@
   a
  -1
  -a1
  -a2
  +m1
  +m2
  diff --git a/x/y b/x/y
  new file mode 100644
  --- /dev/null
  +++ b/x/y
  @@ -0,0 +1,1 @@
  +y1
  
  
single rename

  $ tb "hg mv a b" "add b b1" "add b w"
  % add a 2
  % hg ci -m t0
  created new head
  % hg mv a b
  % hg ci -m t1
  % add b b1
  % hg ci -m t2
  % add b w
  
  # working to parent:
  
  % hg st -C 
  M b
  
  % hg diff --git 
  diff --git a/b b/b
  --- a/b
  +++ b/b
  @@ -1,3 +1,4 @@
   a
   2
   b1
  +w
  
  # working to root:
  
  % hg st -C --rev 0
  A b
    a
  R a
  
  % hg diff --git --rev 0
  diff --git a/a b/b
  rename from a
  rename to b
  --- a/a
  +++ b/b
  @@ -1,1 +1,4 @@
   a
  +2
  +b1
  +w
  
  # working to branch:
  
  % hg st -C --rev 2
  A b
    a
  R a
  R x/y
  
  % hg diff --git --rev 2
  diff --git a/a b/b
  rename from a
  rename to b
  --- a/a
  +++ b/b
  @@ -1,3 +1,4 @@
   a
  -m1
  -m2
  +2
  +b1
  +w
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # root to parent:
  
  % hg st -C --rev 0 --rev .
  A b
    a
  R a
  
  % hg diff --git --rev 0 --rev .
  diff --git a/a b/b
  rename from a
  rename to b
  --- a/a
  +++ b/b
  @@ -1,1 +1,3 @@
   a
  +2
  +b1
  
  # parent to root:
  
  % hg st -C --rev . --rev 0
  A a
    b
  R b
  
  % hg diff --git --rev . --rev 0
  diff --git a/b b/a
  rename from b
  rename to a
  --- a/b
  +++ b/a
  @@ -1,3 +1,1 @@
   a
  -2
  -b1
  
  # branch to parent:
  
  % hg st -C --rev 2 --rev .
  A b
    a
  R a
  R x/y
  
  % hg diff --git --rev 2 --rev .
  diff --git a/a b/b
  rename from a
  rename to b
  --- a/a
  +++ b/b
  @@ -1,3 +1,3 @@
   a
  -m1
  -m2
  +2
  +b1
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # parent to branch:
  
  % hg st -C --rev . --rev 2
  A a
    b
  A x/y
  R b
  
  % hg diff --git --rev . --rev 2
  diff --git a/b b/a
  rename from b
  rename to a
  --- a/b
  +++ b/a
  @@ -1,3 +1,3 @@
   a
  -2
  -b1
  +m1
  +m2
  diff --git a/x/y b/x/y
  new file mode 100644
  --- /dev/null
  +++ b/x/y
  @@ -0,0 +1,1 @@
  +y1
  
  
single copy

  $ tb "hg cp a b" "add b b1" "add a w"
  % add a 3
  % hg ci -m t0
  created new head
  % hg cp a b
  % hg ci -m t1
  % add b b1
  % hg ci -m t2
  % add a w
  
  # working to parent:
  
  % hg st -C 
  M a
  
  % hg diff --git 
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,2 +1,3 @@
   a
   3
  +w
  
  # working to root:
  
  % hg st -C --rev 0
  M a
  A b
    a
  
  % hg diff --git --rev 0
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,3 @@
   a
  +3
  +w
  diff --git a/a b/b
  copy from a
  copy to b
  --- a/a
  +++ b/b
  @@ -1,1 +1,3 @@
   a
  +3
  +b1
  
  # working to branch:
  
  % hg st -C --rev 2
  M a
  A b
    a
  R x/y
  
  % hg diff --git --rev 2
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,3 +1,3 @@
   a
  -m1
  -m2
  +3
  +w
  diff --git a/a b/b
  copy from a
  copy to b
  --- a/a
  +++ b/b
  @@ -1,3 +1,3 @@
   a
  -m1
  -m2
  +3
  +b1
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # root to parent:
  
  % hg st -C --rev 0 --rev .
  M a
  A b
    a
  
  % hg diff --git --rev 0 --rev .
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,2 @@
   a
  +3
  diff --git a/a b/b
  copy from a
  copy to b
  --- a/a
  +++ b/b
  @@ -1,1 +1,3 @@
   a
  +3
  +b1
  
  # parent to root:
  
  % hg st -C --rev . --rev 0
  M a
  R b
  
  % hg diff --git --rev . --rev 0
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,2 +1,1 @@
   a
  -3
  diff --git a/b b/b
  deleted file mode 100644
  --- a/b
  +++ /dev/null
  @@ -1,3 +0,0 @@
  -a
  -3
  -b1
  
  # branch to parent:
  
  % hg st -C --rev 2 --rev .
  M a
  A b
    a
  R x/y
  
  % hg diff --git --rev 2 --rev .
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,3 +1,2 @@
   a
  -m1
  -m2
  +3
  diff --git a/a b/b
  copy from a
  copy to b
  --- a/a
  +++ b/b
  @@ -1,3 +1,3 @@
   a
  -m1
  -m2
  +3
  +b1
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # parent to branch:
  
  % hg st -C --rev . --rev 2
  M a
  A x/y
  R b
  
  % hg diff --git --rev . --rev 2
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,2 +1,3 @@
   a
  -3
  +m1
  +m2
  diff --git a/b b/b
  deleted file mode 100644
  --- a/b
  +++ /dev/null
  @@ -1,3 +0,0 @@
  -a
  -3
  -b1
  diff --git a/x/y b/x/y
  new file mode 100644
  --- /dev/null
  +++ b/x/y
  @@ -0,0 +1,1 @@
  +y1
  
  
rename chain

  $ tb "hg mv a b" "hg mv b c" "hg mv c d"
  % add a 4
  % hg ci -m t0
  created new head
  % hg mv a b
  % hg ci -m t1
  % hg mv b c
  % hg ci -m t2
  % hg mv c d
  
  # working to parent:
  
  % hg st -C 
  A d
    c
  R c
  
  % hg diff --git 
  diff --git a/c b/d
  rename from c
  rename to d
  
  # working to root:
  
  % hg st -C --rev 0
  A d
    a
  R a
  
  % hg diff --git --rev 0
  diff --git a/a b/d
  rename from a
  rename to d
  --- a/a
  +++ b/d
  @@ -1,1 +1,2 @@
   a
  +4
  
  # working to branch:
  
  % hg st -C --rev 2
  A d
    a
  R a
  R x/y
  
  % hg diff --git --rev 2
  diff --git a/a b/d
  rename from a
  rename to d
  --- a/a
  +++ b/d
  @@ -1,3 +1,2 @@
   a
  -m1
  -m2
  +4
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # root to parent:
  
  % hg st -C --rev 0 --rev .
  A c
    a
  R a
  
  % hg diff --git --rev 0 --rev .
  diff --git a/a b/c
  rename from a
  rename to c
  --- a/a
  +++ b/c
  @@ -1,1 +1,2 @@
   a
  +4
  
  # parent to root:
  
  % hg st -C --rev . --rev 0
  A a
    c
  R c
  
  % hg diff --git --rev . --rev 0
  diff --git a/c b/a
  rename from c
  rename to a
  --- a/c
  +++ b/a
  @@ -1,2 +1,1 @@
   a
  -4
  
  # branch to parent:
  
  % hg st -C --rev 2 --rev .
  A c
    a
  R a
  R x/y
  
  % hg diff --git --rev 2 --rev .
  diff --git a/a b/c
  rename from a
  rename to c
  --- a/a
  +++ b/c
  @@ -1,3 +1,2 @@
   a
  -m1
  -m2
  +4
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # parent to branch:
  
  % hg st -C --rev . --rev 2
  A a
    c
  A x/y
  R c
  
  % hg diff --git --rev . --rev 2
  diff --git a/c b/a
  rename from c
  rename to a
  --- a/c
  +++ b/a
  @@ -1,2 +1,3 @@
   a
  -4
  +m1
  +m2
  diff --git a/x/y b/x/y
  new file mode 100644
  --- /dev/null
  +++ b/x/y
  @@ -0,0 +1,1 @@
  +y1
  
  
copy chain

  $ tb "hg cp a b" "hg cp b c" "hg cp c d"
  % add a 5
  % hg ci -m t0
  created new head
  % hg cp a b
  % hg ci -m t1
  % hg cp b c
  % hg ci -m t2
  % hg cp c d
  
  # working to parent:
  
  % hg st -C 
  A d
    c
  
  % hg diff --git 
  diff --git a/c b/d
  copy from c
  copy to d
  
  # working to root:
  
  % hg st -C --rev 0
  M a
  A b
    a
  A c
    a
  A d
    a
  
  % hg diff --git --rev 0
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,2 @@
   a
  +5
  diff --git a/a b/b
  copy from a
  copy to b
  --- a/a
  +++ b/b
  @@ -1,1 +1,2 @@
   a
  +5
  diff --git a/a b/c
  copy from a
  copy to c
  --- a/a
  +++ b/c
  @@ -1,1 +1,2 @@
   a
  +5
  diff --git a/a b/d
  copy from a
  copy to d
  --- a/a
  +++ b/d
  @@ -1,1 +1,2 @@
   a
  +5
  
  # working to branch:
  
  % hg st -C --rev 2
  M a
  A b
    a
  A c
    a
  A d
    a
  R x/y
  
  % hg diff --git --rev 2
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,3 +1,2 @@
   a
  -m1
  -m2
  +5
  diff --git a/a b/b
  copy from a
  copy to b
  --- a/a
  +++ b/b
  @@ -1,3 +1,2 @@
   a
  -m1
  -m2
  +5
  diff --git a/a b/c
  copy from a
  copy to c
  --- a/a
  +++ b/c
  @@ -1,3 +1,2 @@
   a
  -m1
  -m2
  +5
  diff --git a/a b/d
  copy from a
  copy to d
  --- a/a
  +++ b/d
  @@ -1,3 +1,2 @@
   a
  -m1
  -m2
  +5
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # root to parent:
  
  % hg st -C --rev 0 --rev .
  M a
  A b
    a
  A c
    a
  
  % hg diff --git --rev 0 --rev .
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,2 @@
   a
  +5
  diff --git a/a b/b
  copy from a
  copy to b
  --- a/a
  +++ b/b
  @@ -1,1 +1,2 @@
   a
  +5
  diff --git a/a b/c
  copy from a
  copy to c
  --- a/a
  +++ b/c
  @@ -1,1 +1,2 @@
   a
  +5
  
  # parent to root:
  
  % hg st -C --rev . --rev 0
  M a
  R b
  R c
  
  % hg diff --git --rev . --rev 0
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,2 +1,1 @@
   a
  -5
  diff --git a/b b/b
  deleted file mode 100644
  --- a/b
  +++ /dev/null
  @@ -1,2 +0,0 @@
  -a
  -5
  diff --git a/c b/c
  deleted file mode 100644
  --- a/c
  +++ /dev/null
  @@ -1,2 +0,0 @@
  -a
  -5
  
  # branch to parent:
  
  % hg st -C --rev 2 --rev .
  M a
  A b
    a
  A c
    a
  R x/y
  
  % hg diff --git --rev 2 --rev .
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,3 +1,2 @@
   a
  -m1
  -m2
  +5
  diff --git a/a b/b
  copy from a
  copy to b
  --- a/a
  +++ b/b
  @@ -1,3 +1,2 @@
   a
  -m1
  -m2
  +5
  diff --git a/a b/c
  copy from a
  copy to c
  --- a/a
  +++ b/c
  @@ -1,3 +1,2 @@
   a
  -m1
  -m2
  +5
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # parent to branch:
  
  % hg st -C --rev . --rev 2
  M a
  A x/y
  R b
  R c
  
  % hg diff --git --rev . --rev 2
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,2 +1,3 @@
   a
  -5
  +m1
  +m2
  diff --git a/b b/b
  deleted file mode 100644
  --- a/b
  +++ /dev/null
  @@ -1,2 +0,0 @@
  -a
  -5
  diff --git a/c b/c
  deleted file mode 100644
  --- a/c
  +++ /dev/null
  @@ -1,2 +0,0 @@
  -a
  -5
  diff --git a/x/y b/x/y
  new file mode 100644
  --- /dev/null
  +++ b/x/y
  @@ -0,0 +1,1 @@
  +y1
  
  
circular rename

  $ tb "add a a1" "hg mv a b" "hg mv b a"
  % add a 6
  % hg ci -m t0
  created new head
  % add a a1
  % hg ci -m t1
  % hg mv a b
  % hg ci -m t2
  % hg mv b a
  
  # working to parent:
  
  % hg st -C 
  A a
    b
  R b
  
  % hg diff --git 
  diff --git a/b b/a
  rename from b
  rename to a
  
  # working to root:
  
  % hg st -C --rev 0
  M a
  
  % hg diff --git --rev 0
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,3 @@
   a
  +6
  +a1
  
  # working to branch:
  
  % hg st -C --rev 2
  M a
  R x/y
  
  % hg diff --git --rev 2
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,3 +1,3 @@
   a
  -m1
  -m2
  +6
  +a1
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # root to parent:
  
  % hg st -C --rev 0 --rev .
  A b
    a
  R a
  
  % hg diff --git --rev 0 --rev .
  diff --git a/a b/b
  rename from a
  rename to b
  --- a/a
  +++ b/b
  @@ -1,1 +1,3 @@
   a
  +6
  +a1
  
  # parent to root:
  
  % hg st -C --rev . --rev 0
  A a
    b
  R b
  
  % hg diff --git --rev . --rev 0
  diff --git a/b b/a
  rename from b
  rename to a
  --- a/b
  +++ b/a
  @@ -1,3 +1,1 @@
   a
  -6
  -a1
  
  # branch to parent:
  
  % hg st -C --rev 2 --rev .
  A b
    a
  R a
  R x/y
  
  % hg diff --git --rev 2 --rev .
  diff --git a/a b/b
  rename from a
  rename to b
  --- a/a
  +++ b/b
  @@ -1,3 +1,3 @@
   a
  -m1
  -m2
  +6
  +a1
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  
  # parent to branch:
  
  % hg st -C --rev . --rev 2
  A a
    b
  A x/y
  R b
  
  % hg diff --git --rev . --rev 2
  diff --git a/b b/a
  rename from b
  rename to a
  --- a/b
  +++ b/a
  @@ -1,3 +1,3 @@
   a
  -6
  -a1
  +m1
  +m2
  diff --git a/x/y b/x/y
  new file mode 100644
  --- /dev/null
  +++ b/x/y
  @@ -0,0 +1,1 @@
  +y1
  
  
directory move

  $ tb "hg mv x y" "add y/x x1" "add y/x x2"
  % add a 7
  % hg ci -m t0
  created new head
  % hg mv x y
  moving x/x to y/x (glob)
  % hg ci -m t1
  % add y/x x1
  % hg ci -m t2
  % add y/x x2
  
  # working to parent:
  
  % hg st -C 
  M y/x
  
  % hg diff --git 
  diff --git a/y/x b/y/x
  --- a/y/x
  +++ b/y/x
  @@ -1,2 +1,3 @@
   x
   x1
  +x2
  
  # working to root:
  
  % hg st -C --rev 0
  M a
  A y/x
    x/x
  R x/x
  
  % hg diff --git --rev 0
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,2 @@
   a
  +7
  diff --git a/x/x b/y/x
  rename from x/x
  rename to y/x
  --- a/x/x
  +++ b/y/x
  @@ -1,1 +1,3 @@
   x
  +x1
  +x2
  
  # working to branch:
  
  % hg st -C --rev 2
  M a
  A y/x
    x/x
  R x/x
  R x/y
  
  % hg diff --git --rev 2
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,3 +1,2 @@
   a
  -m1
  -m2
  +7
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  diff --git a/x/x b/y/x
  rename from x/x
  rename to y/x
  --- a/x/x
  +++ b/y/x
  @@ -1,1 +1,3 @@
   x
  +x1
  +x2
  
  # root to parent:
  
  % hg st -C --rev 0 --rev .
  M a
  A y/x
    x/x
  R x/x
  
  % hg diff --git --rev 0 --rev .
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,2 @@
   a
  +7
  diff --git a/x/x b/y/x
  rename from x/x
  rename to y/x
  --- a/x/x
  +++ b/y/x
  @@ -1,1 +1,2 @@
   x
  +x1
  
  # parent to root:
  
  % hg st -C --rev . --rev 0
  M a
  A x/x
    y/x
  R y/x
  
  % hg diff --git --rev . --rev 0
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,2 +1,1 @@
   a
  -7
  diff --git a/y/x b/x/x
  rename from y/x
  rename to x/x
  --- a/y/x
  +++ b/x/x
  @@ -1,2 +1,1 @@
   x
  -x1
  
  # branch to parent:
  
  % hg st -C --rev 2 --rev .
  M a
  A y/x
    x/x
  R x/x
  R x/y
  
  % hg diff --git --rev 2 --rev .
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,3 +1,2 @@
   a
  -m1
  -m2
  +7
  diff --git a/x/y b/x/y
  deleted file mode 100644
  --- a/x/y
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -y1
  diff --git a/x/x b/y/x
  rename from x/x
  rename to y/x
  --- a/x/x
  +++ b/y/x
  @@ -1,1 +1,2 @@
   x
  +x1
  
  # parent to branch:
  
  % hg st -C --rev . --rev 2
  M a
  A x/x
    y/x
  A x/y
  R y/x
  
  % hg diff --git --rev . --rev 2
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,2 +1,3 @@
   a
  -7
  +m1
  +m2
  diff --git a/y/x b/x/x
  rename from y/x
  rename to x/x
  --- a/y/x
  +++ b/x/x
  @@ -1,2 +1,1 @@
   x
  -x1
  diff --git a/x/y b/x/y
  new file mode 100644
  --- /dev/null
  +++ b/x/y
  @@ -0,0 +1,1 @@
  +y1
  
  

Cannot implement unrelated branch with tb
testing copies with unrelated branch

  $ hg init unrelated
  $ cd unrelated
  $ echo a >> a
  $ hg ci -Am adda
  adding a
  $ hg mv a b
  $ hg ci -m movea
  $ hg up -C null
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo a >> a
  $ hg ci -Am addunrelateda
  adding a
  created new head

unrelated branch diff

  $ hg diff --git -r 2 -r 1
  diff --git a/a b/a
  deleted file mode 100644
  --- a/a
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -a
  diff --git a/b b/b
  new file mode 100644
  --- /dev/null
  +++ b/b
  @@ -0,0 +1,1 @@
  +a
  $ cd ..


test for case where we didn't look sufficiently far back to find rename ancestor

  $ hg init diffstop
  $ cd diffstop
  $ echo > f
  $ hg ci -qAmf
  $ hg mv f g
  $ hg ci -m'f->g'
  $ hg up -qr0
  $ touch x
  $ hg ci -qAmx
  $ echo f > f
  $ hg ci -qmf=f
  $ hg merge -q
  $ hg ci -mmerge
  $ hg log -G --template '{rev}  {desc}'
  @    4  merge
  |\
  | o  3  f=f
  | |
  | o  2  x
  | |
  o |  1  f->g
  |/
  o  0  f
  
  $ hg diff --git -r 2
  diff --git a/f b/g
  rename from f
  rename to g
  --- a/f
  +++ b/g
  @@ -1,1 +1,1 @@
  -
  +f
  $ cd ..

Additional tricky linkrev case
------------------------------

If the first file revision after the diff base has a linkrev pointing to a
changeset on another branch with a revision lower that the diff base, we can
jump past the copy detection limit and fail to detect the rename.

  $ hg init diffstoplinkrev
  $ cd diffstoplinkrev

  $ touch f
  $ hg ci -Aqm 'empty f'

Make a simple change

  $ echo change > f
  $ hg ci -m 'change f'

Make a second branch, we use a named branch to create a simple commit
that does not touch f.

  $ hg up -qr 'desc(empty)'
  $ hg branch -q dev
  $ hg ci -Aqm dev

Graft the initial change, as f was untouched, we reuse the same entry and the
linkrev point to the older branch.

  $ hg graft -q 'desc(change)'

Make a rename because we want to track renames. It is also important that the
faulty linkrev is not the "start" commit to ensure the linkrev will be used.

  $ hg mv f renamed
  $ hg ci -m renamed

  $ hg log -G -T '{rev} {desc}'
  @  4 renamed
  |
  o  3 change f
  |
  o  2 dev
  |
  | o  1 change f
  |/
  o  0 empty f
  

The copy tracking should still reach rev 2 (branch creation).
accessing the parent of 4 (renamed) should not jump use to revision 1.

  $ hg diff --git -r 'desc(dev)' -r .
  diff --git a/f b/renamed
  rename from f
  rename to renamed
  --- a/f
  +++ b/renamed
  @@ -0,0 +1,1 @@
  +change

  $ cd ..