view tests/test-mv-cp-st-diff.t @ 30580:51e7c83e05ee

rebase: calculate ancestors for --base separately (issue5420)

Previously, the --base option only works with a single "branch" - if there
is one changeset in the "--base" revset whose branching point(s) is/are
different from another changeset in the "--base" revset, "rebase" will error
out with:

  abort: source is ancestor of destination

This happens if the user has multiple draft branches, and uses "hg rebase -b
'draft()' -d master", for example. The error message looks cryptic to users
who don't know the implementation detail.

This patch changes the logic to calculate the common ancestor for every
"base" changeset separately so we won't (incorrectly) select "source" which
is an ancestor of the destination.

This patch should not change the behavior where all changesets specified by
"--base" have the same branching point(s).

A new situation is: some of the specified changesets could be rebased, while
some couldn't (because they are descendants of the destination, or they do
not share a common ancestor with the destination). The current behavior is
to show "nothing to rebase" and exits with 1.

This patch maintains the current behavior (show "nothing to rebase") even if
part of the "--base" revset could be rebased. A clearer error message may be
"cannot find branching point for X", or "X is a descendant of destination".
The error message issue is tracked by issue5422 separately.

A test is added with all kinds of tricky cases I could think of for now.

  $ 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 ..