tests/test-mv-cp-st-diff.t
author Pierre-Yves David <pierre-yves.david@fb.com>
Tue, 23 Dec 2014 15:30:38 -0800
changeset 23702 c48924787eaa
parent 20294 243ea5ffdf31
child 35393 4441705b7111
permissions -rw-r--r--
filectx.parents: enforce changeid of parent to be in own changectx ancestors Because of the way filenodes are computed, you can have multiple changesets "introducing" the same file revision. For example, in the changeset graph below, changeset 2 and 3 both change a file -to- and -from- the same content. o 3: content = new | | o 2: content = new |/ o 1: content = old In such cases, the file revision is create once, when 2 is added, and just reused for 3. So the file change in '3' (from "old" to "new)" has no linkrev pointing to it). We'll call this situation "linkrev-shadowing". As the linkrev is used for optimization purposes when walking a file history, the linkrev-shadowing results in an unexpected jump to another branch during such a walk.. This leads to multiple bugs with log, annotate and rename detection. One element to fix such bugs is to ensure that walking the file history sticks on the same topology as the changeset's history. For this purpose, we extend the logic in 'basefilectx.parents' so that it always defines the proper changeset to associate the parent file revision with. This "proper" changeset has to be an ancestor of the changeset associated with the child file revision. This logic is performed in the '_adjustlinkrev' function. This function is given the starting changeset and all the information regarding the parent file revision. If the linkrev for the file revision is an ancestor of the starting changeset, the linkrev is valid and will be used. If it is not, we detected a topological jump caused by linkrev shadowing, we are going to walk the ancestors of the starting changeset until we find one setting the file to the revision we are trying to create. The performance impact appears acceptable: - We are walking the changelog once for each filelog traversal (as there should be no overlap between searches), - changelog traversal itself is fairly cheap, compared to what is likely going to be perform on the result on the filelog traversal, - We only touch the manifest for ancestors touching the file, And such changesets are likely to be the one introducing the file. (except in pathological cases involving merge), - We use manifest diff instead of full manifest unpacking to check manifest content, so it does not involve applying multiple diffs in most case. - linkrev shadowing is not the common case. Tests for fixed issues in log, annotate and rename detection have been added. But this changeset does not solve all problems. It fixes -ancestry- computation, but if the linkrev-shadowed changesets is the starting one, we'll still get things wrong. We'll have to fix the bootstrapping of such operations in a later changeset. Also, the usage of `hg log FILE` without --follow still has issues with linkrev pointing to hidden changesets, because it relies on the `filelog` revset which implement its own traversal logic that is still to be fixed. Thanks goes to: - Matt Mackall: for nudging me in the right direction - Julien Cristau and RĂ©mi Cardona: for keep telling me linkrev bug were an evolution show stopper for 3 years. - Durham Goode: for finding a new linkrev issue every few weeks - Mads Kiilerich: for that last rename bug who raise this topic over my anoyance limit.


  $ 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 ..