copies-tests: add a case where with merge with an overwritten files

This is similar to the BF/FB case, but in this case, the other branch updated
the file. So an actual merge happens and the two "independant" file history has
to be merged.

Differential Revision: https://phab.mercurial-scm.org/D8242

tests/test-copies-chain-merge.t

@@ -1,755 +1,869 b''
 =====================================================
 Test Copy tracing for chain of copies involving merge
 =====================================================
 
 This test files covers copies/rename case for a chains of commit where merges
 are involved. It cheks we do not have unwanted update of behavior and that the
 different options to retrieve copies behave correctly.
 
 Setup
 =====
 
 use git diff to see rename
 
   $ cat << EOF >> $HGRCPATH
   > [diff]
   > git=yes
   > [ui]
   > logtemplate={rev} {desc}]\n
   > EOF
 
   $ hg init repo-chain
   $ cd repo-chain
 
 Add some linear rename initialy
 
   $ touch a b h
   $ hg ci -Am 'i-0 initial commit: a b h'
   adding a
   adding b
   adding h
   $ hg mv a c
   $ hg ci -Am 'i-1: a -move-> c'
   $ hg mv c d
   $ hg ci -Am 'i-2: c -move-> d'
   $ hg log -G
   @  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 And having another branch with renames on the other side
 
   $ hg mv d e
   $ hg ci -Am 'a-1: d -move-> e'
   $ hg mv e f
   $ hg ci -Am 'a-2: e -move-> f'
   $ hg log -G --rev '::.'
   @  4 a-2: e -move-> f]
   |
   o  3 a-1: d -move-> e]
   |
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 Have a branching with nothing on one side
 
   $ hg up 'desc("i-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ echo foo > b
   $ hg ci -m 'b-1: b update'
   created new head
   $ hg log -G --rev '::.'
   @  5 b-1: b update]
   |
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 
 Merge the two branches we just defined (in both directions)
 - one with change to an unrelated file
 - one with renames in them
 
   $ hg up 'desc("b-1")'
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("a-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mBAm-0 simple merge - one way'
   $ hg up 'desc("a-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mABm-0 simple merge - the other way'
   created new head
   $ hg log -G --rev '::(desc("mABm")+desc("mBAm"))'
   @    7 mABm-0 simple merge - the other way]
   |\
   +---o  6 mBAm-0 simple merge - one way]
   | |/
   | o  5 b-1: b update]
   | |
   o |  4 a-2: e -move-> f]
   | |
   o |  3 a-1: d -move-> e]
   |/
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 Create a branch that delete a file previous renamed
 
   $ hg up 'desc("i-2")'
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg rm d
   $ hg ci -m 'c-1 delete d'
   created new head
   $ hg log -G --rev '::.'
   @  8 c-1 delete d]
   |
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 Merge:
 - one with change to an unrelated file
 - one deleting the change
 and recreate an unrelated file after the merge
 
   $ hg up 'desc("b-1")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("c-1")'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mBCm-0 simple merge - one way'
   $ echo bar > d
   $ hg add d
   $ hg ci -m 'mBCm-1 re-add d'
   $ hg up 'desc("c-1")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mCBm-0 simple merge - the other way'
   created new head
   $ echo bar > d
   $ hg add d
   $ hg ci -m 'mCBm-1 re-add d'
   $ hg log -G --rev '::(desc("mCBm")+desc("mBCm"))'
   @  12 mCBm-1 re-add d]
   |
   o    11 mCBm-0 simple merge - the other way]
   |\
   | | o  10 mBCm-1 re-add d]
   | | |
   +---o  9 mBCm-0 simple merge - one way]
   | |/
   | o  8 c-1 delete d]
   | |
   o |  5 b-1: b update]
   |/
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 Create a branch that delete a file previous renamed and recreate it
 
   $ hg up 'desc("i-2")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg rm d
   $ hg ci -m 'd-1 delete d'
   created new head
   $ echo bar > d
   $ hg add d
   $ hg ci -m 'd-2 re-add d'
   $ hg log -G --rev '::.'
   @  14 d-2 re-add d]
   |
   o  13 d-1 delete d]
   |
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 Merge:
 - one with change to an unrelated file
 - one deleting and recreating the file
 
 Note:
 | In this case, the merge get conflicting information since on one side we have
 | a "brand new" d. and one the other one we have "d renamed from c (itself
 | renamed from c)".
 |
 | The current code arbitrarily pick one side
 
   $ hg up 'desc("b-1")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("d-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mBDm-0 simple merge - one way'
   $ hg up 'desc("d-2")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mDBm-0 simple merge - the other way'
   created new head
   $ hg log -G --rev '::(desc("mDBm")+desc("mBDm"))'
   @    16 mDBm-0 simple merge - the other way]
   |\
   +---o  15 mBDm-0 simple merge - one way]
   | |/
   | o  14 d-2 re-add d]
   | |
   | o  13 d-1 delete d]
   | |
   o |  5 b-1: b update]
   |/
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 Having another branch renaming a different file to the same filename as another
 
   $ hg up 'desc("i-2")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg mv b g
   $ hg ci -m 'e-1 b -move-> g'
   created new head
   $ hg mv g f
   $ hg ci -m 'e-2 g -move-> f'
   $ hg log -G --rev '::.'
   @  18 e-2 g -move-> f]
   |
   o  17 e-1 b -move-> g]
   |
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 Merge:
 - the "e-" branch renaming b to f (through 'g')
 - the "a-" branch renaming d to f (through e)
 
   $ hg up 'desc("a-2")'
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("e-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mAEm-0 simple merge - one way'
   $ hg up 'desc("e-2")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("a-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mEAm-0 simple merge - the other way'
   created new head
   $ hg log -G --rev '::(desc("mAEm")+desc("mEAm"))'
   @    20 mEAm-0 simple merge - the other way]
   |\
   +---o  19 mAEm-0 simple merge - one way]
   | |/
   | o  18 e-2 g -move-> f]
   | |
   | o  17 e-1 b -move-> g]
   | |
   o |  4 a-2: e -move-> f]
   | |
   o |  3 a-1: d -move-> e]
   |/
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 Note:
 | In this case, one of the merge wrongly record a merge while there is none.
 | This lead to bad copy tracing information to be dug up.
 
 
 Merge:
 - one with change to an unrelated file (b)
 - one overwriting a file (d) with a rename (from h to i to d)
 
   $ hg up 'desc("i-2")'
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg mv h i
   $ hg commit -m "f-1: rename h -> i"
   created new head
   $ hg mv --force i d
   $ hg commit -m "f-2: rename i -> d"
   $ hg debugindex d
      rev linkrev nodeid       p1           p2
        0       2 01c2f5eabdc4 000000000000 000000000000
        1      10 b004912a8510 000000000000 000000000000
        2      15 0bb5445dc4d0 01c2f5eabdc4 b004912a8510
        3      22 c72365ee036f 000000000000 000000000000
   $ hg up 'desc("b-1")'
   3 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("f-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mBFm-0 simple merge - one way'
   $ hg up 'desc("f-2")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mFBm-0 simple merge - the other way'
   created new head
   $ hg log -G --rev '::(desc("mBFm")+desc("mFBm"))'
   @    24 mFBm-0 simple merge - the other way]
   |\
   +---o  23 mBFm-0 simple merge - one way]
   | |/
   | o  22 f-2: rename i -> d]
   | |
   | o  21 f-1: rename h -> i]
   | |
   o |  5 b-1: b update]
   |/
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 Merge:
 - one with change to a file
 - one deleting and recreating the file
 
   $ hg up 'desc("i-2")'
   3 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ echo "some update" >> d
   $ hg commit -m "g-1: update d"
   created new head
   $ hg up 'desc("d-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("g-1")' --tool :union
   merging d
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mDGm-0 simple merge - one way'
   $ hg up 'desc("g-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("d-2")' --tool :union
   merging d
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mGDm-0 simple merge - the other way'
   created new head
   $ hg log -G --rev '::(desc("mDGm")+desc("mGDm"))'
   @    27 mGDm-0 simple merge - the other way]
   |\
   +---o  26 mDGm-0 simple merge - one way]
   | |/
   | o  25 g-1: update d]
   | |
   o |  14 d-2 re-add d]
   | |
   o |  13 d-1 delete d]
   |/
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 
+Merge:
+- one with change to a file (d)
+- one overwriting that file with a rename (from h to i, to d)
+
+  $ hg up 'desc("f-2")'
+  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ hg merge 'desc("g-1")' --tool :union
+  merging d
+  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
+  (branch merge, don't forget to commit)
+  $ hg ci -m 'mFGm-0 simple merge - one way'
+  created new head
+  $ hg up 'desc("g-1")'
+  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg merge 'desc("f-2")' --tool :union
+  merging d
+  0 files updated, 1 files merged, 1 files removed, 0 files unresolved
+  (branch merge, don't forget to commit)
+  $ hg ci -m 'mGFm-0 simple merge - the other way'
+  created new head
+  $ hg log -G --rev '::(desc("mGFm")+desc("mFGm"))'
+  @    29 mGFm-0 simple merge - the other way]
+  |\
+  +---o  28 mFGm-0 simple merge - one way]
+  | |/
+  | o  25 g-1: update d]
+  | |
+  o |  22 f-2: rename i -> d]
+  | |
+  o |  21 f-1: rename h -> i]
+  |/
+  o  2 i-2: c -move-> d]
+  |
+  o  1 i-1: a -move-> c]
+  |
+  o  0 i-0 initial commit: a b h]
+  
+
+
 Check results
 =============
 
 merging with unrelated change does not interfer wit the renames
 ---------------------------------------------------------------
 
 - rename on one side
 - unrelated change on the other side
 
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mABm")'
   A f
     d
   R d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBAm")'
   A f
     d
   R d
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mABm")'
   M b
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mBAm")'
   M b
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mABm")'
   M b
   A f
     d
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mBAm")'
   M b
   A f
     d
   R d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mABm")'
   M b
   A f
     a
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBAm")'
   M b
   A f
     a
   R a
 
 merging with the side having a delete
 -------------------------------------
 
 case summary:
 - one with change to an unrelated file
 - one deleting the change
 and recreate an unrelated file after the merge
 
 checks:
 - comparing from the merge
 
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBCm-0")'
   R d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mCBm-0")'
   R d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mBCm-0")'
   M b
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCBm-0")'
   M b
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mBCm-0")'
   M b
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mCBm-0")'
   M b
   R d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBCm-0")'
   M b
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCBm-0")'
   M b
   R a
 
 - comparing with the merge children re-adding the file
 
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBCm-1")'
   M d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mCBm-1")'
   M d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mBCm-1")'
   M b
   A d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCBm-1")'
   M b
   A d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mBCm-1")'
   M b
   M d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mCBm-1")'
   M b
   M d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBCm-1")'
   M b
   A d
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCBm-1")'
   M b
   A d
   R a
 
 Comparing with a merge re-adding the file afterward
 ---------------------------------------------------
 
 Merge:
 - one with change to an unrelated file
 - one deleting and recreating the change
 
 Note:
 | In this case, one of the merge wrongly record a merge while there is none.
 | This lead to bad copy tracing information to be dug up.
 
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBDm-0")'
   M d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mDBm-0")'
   M d
   $ hg status --copies --rev 'desc("d-2")' --rev 'desc("mBDm-0")'
   M b
   M d
   $ hg status --copies --rev 'desc("d-2")' --rev 'desc("mDBm-0")'
   M b
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mBDm-0")'
   M b
   M d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mDBm-0")'
   M b
   M d
 
 The bugs makes recorded copy is different depending of where we started the merge from since
 
   $ hg manifest --debug --rev 'desc("mBDm-0")' | grep '644   d'
   0bb5445dc4d02f4e0d86cf16f9f3a411d0f17744 644   d
   $ hg manifest --debug --rev 'desc("mDBm-0")' | grep '644   d'
   b004912a8510032a0350a74daa2803dadfb00e12 644   d
 
 The 0bb5445dc4d02f4e0d86cf16f9f3a411d0f17744 entry is wrong, since the file was
 deleted on one side (then recreate) and untouched on the other side, no "merge"
 has happened. The resulting `d` file is the untouched version from branch `D`,
 not a merge.
 
   $ hg manifest --debug --rev 'desc("d-2")' | grep '644   d'
   b004912a8510032a0350a74daa2803dadfb00e12 644   d
   $ hg manifest --debug --rev 'desc("b-1")' | grep '644   d'
   01c2f5eabdc4ce2bdee42b5f86311955e6c8f573 644   d
   $ hg debugindex d
      rev linkrev nodeid       p1           p2
        0       2 01c2f5eabdc4 000000000000 000000000000
        1      10 b004912a8510 000000000000 000000000000
        2      15 0bb5445dc4d0 01c2f5eabdc4 b004912a8510
        3      22 c72365ee036f 000000000000 000000000000
        4      23 863d9bc49190 01c2f5eabdc4 c72365ee036f
        5      25 7bded9d9da1f 01c2f5eabdc4 000000000000
        6      26 f04cac32d703 b004912a8510 7bded9d9da1f
        7      27 d7a5eafb9322 7bded9d9da1f b004912a8510
+       8      28 2ed7a51aed47 c72365ee036f 7bded9d9da1f
 
 (This `hg log` output if wrong, since no merge actually happened).
 
   $ hg log -Gfr 'desc("mBDm-0")' d
   o    15 mBDm-0 simple merge - one way]
   |\
   o :  14 d-2 re-add d]
   :/
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 This `hg log` output is correct
 
   $ hg log -Gfr 'desc("mDBm-0")' d
   o  14 d-2 re-add d]
   |
   ~
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBDm-0")'
   M b
   A d
     a
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mDBm-0")'
   M b
   A d
   R a
 
 Comparing with a merge with colliding rename
 --------------------------------------------
 
 - the "e-" branch renaming b to f (through 'g')
 - the "a-" branch renaming d to f (through e)
 
   $ hg manifest --debug --rev 'desc("mAEm-0")' | grep '644   f'
   eb806e34ef6be4c264effd5933d31004ad15a793 644   f
   $ hg manifest --debug --rev 'desc("mEAm-0")' | grep '644   f'
   eb806e34ef6be4c264effd5933d31004ad15a793 644   f
   $ hg manifest --debug --rev 'desc("a-2")' | grep '644   f'
   0dd616bc7ab1a111921d95d76f69cda5c2ac539c 644   f
   $ hg manifest --debug --rev 'desc("e-2")' | grep '644   f'
   6da5a2eecb9c833f830b67a4972366d49a9a142c 644   f
   $ hg debugindex f
      rev linkrev nodeid       p1           p2
        0       4 0dd616bc7ab1 000000000000 000000000000
        1      18 6da5a2eecb9c 000000000000 000000000000
        2      19 eb806e34ef6b 0dd616bc7ab1 6da5a2eecb9c
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mAEm-0")'
   M f
   R b
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mEAm-0")'
   M f
   R b
   $ hg status --copies --rev 'desc("e-2")' --rev 'desc("mAEm-0")'
   M f
   R d
   $ hg status --copies --rev 'desc("e-2")' --rev 'desc("mEAm-0")'
   M f
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("a-2")'
   A f
     d
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("e-2")'
   A f
     b
   R b
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mAEm-0")'
   A f
     d
   R b
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mEAm-0")'
   A f
     d
   R b
   R d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mAEm-0")'
   A f
     a
   R a
   R b
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mEAm-0")'
   A f
     a
   R a
   R b
 
 Merge:
 - one with change to an unrelated file (b)
 - one overwriting a file (d) with a rename (from h to i to d)
 
 The overwriting should take over. However, the behavior is currently buggy
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBFm-0")'
   M b
   A d
     a (true !)
     h (false !)
   R a
   R h
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mFBm-0")'
   M b
   A d
     h
   R a
   R h
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBFm-0")'
   M d
   R h
   $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mBFm-0")'
   M b
   M d
   $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mBFm-0")'
   M b
   M d
   R i
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mFBm-0")'
   M d
   R h
   $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mFBm-0")'
   M b
   $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mFBm-0")'
   M b
   M d
   R i
 
 The following graphlog is wrong, the "a -> c -> d" chain was overwritten and should not appear.
 
   $ hg log -Gfr 'desc("mBFm-0")' d
   o    23 mBFm-0 simple merge - one way]
   |\
   o :  22 f-2: rename i -> d]
   | :
   o :  21 f-1: rename h -> i]
   :/
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 The following output is correct.
 
   $ hg log -Gfr 'desc("mFBm-0")' d
   o  22 f-2: rename i -> d]
   |
   o  21 f-1: rename h -> i]
   :
   o  0 i-0 initial commit: a b h]
   
 
 Merge:
 - one with change to a file
 - one deleting and recreating the file
 
 Unlike in the 'BD/DB' cases, an actuall merge happened here. So we should
 consider history and rename on both branch of the merge.
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mDGm-0")'
   A d
     a
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mGDm-0")'
   A d
     a
   R a
   $ hg status --copies --rev 'desc("d-2")' --rev 'desc("mDGm-0")'
   M d
   $ hg status --copies --rev 'desc("d-2")' --rev 'desc("mGDm-0")'
   M d
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mDGm-0")'
   M d
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mGDm-0")'
   M d
 
   $ hg log -Gfr 'desc("mDGm-0")' d
   o    26 mDGm-0 simple merge - one way]
   |\
   | o  25 g-1: update d]
   | |
   o |  14 d-2 re-add d]
   |/
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
 
 
   $ hg log -Gfr 'desc("mDGm-0")' d
   o    26 mDGm-0 simple merge - one way]
   |\
   | o  25 g-1: update d]
   | |
   o |  14 d-2 re-add d]
   |/
   o  2 i-2: c -move-> d]
   |
   o  1 i-1: a -move-> c]
   |
   o  0 i-0 initial commit: a b h]
   
+
+
+Merge:
+- one with change to a file (d)
+- one overwriting that file with a rename (from h to i, to d)
+
+This case is similar to BF/FB, but an actual merge happens, so both side of the
+history are relevant.
+
+Note:
+| In this case, the merge get conflicting information since on one side we have
+| "a -> c -> d". and one the other one we have "h -> i -> d".
+|
+| The current code arbitrarily pick one side
+
+  $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mFGm-0")'
+  A d
+    a
+  R a
+  R h
+  $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mGFm-0")'
+  A d
+    a
+  R a
+  R h
+  $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mFGm-0")'
+  M d
+  $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mGFm-0")'
+  M d
+  $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mFGm-0")'
+  M d
+  R i
+  $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mGFm-0")'
+  M d
+  R i
+  $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mFGm-0")'
+  M d
+  R h
+  $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mGFm-0")'
+  M d
+  R h
+
+  $ hg log -Gfr 'desc("mFGm-0")' d
+  o    28 mFGm-0 simple merge - one way]
+  |\
+  | o  25 g-1: update d]
+  | |
+  o |  22 f-2: rename i -> d]
+  | |
+  o |  21 f-1: rename h -> i]
+  |/
+  o  2 i-2: c -move-> d]
+  |
+  o  1 i-1: a -move-> c]
+  |
+  o  0 i-0 initial commit: a b h]
+  
+
+
+  $ hg log -Gfr 'desc("mGFm-0")' d
+  @    29 mGFm-0 simple merge - the other way]
+  |\
+  | o  25 g-1: update d]
+  | |
+  o |  22 f-2: rename i -> d]
+  | |
+  o |  21 f-1: rename h -> i]
+  |/
+  o  2 i-2: c -move-> d]
+  |
+  o  1 i-1: a -move-> c]
+  |
+  o  0 i-0 initial commit: a b h]
+