copies-tests: update the analysis of the BD/DB cases

After thinking more about it, the current change in output between the two
merges is not due to an ambiguity, it is introduce by a bug in merge/commit
that record a wrong file history.

Fixing the bug should fix the output. In the meantime, we have a wrong behavior.

In practice the bug is not in the merge code (who does the right things), but in
the commit code (who get confused when recording the new file revision).

Differential Revision: https://phab.mercurial-scm.org/D8237

tests/test-copies-chain-merge.t

@@ -1,584 +1,586 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
   $ hg ci -Am 'i-0 initial commit: a b'
   adding a
   adding b
   $ 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]
   
 
 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]
   
 
 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]
   
 
 
 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]
   
 
 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]
   
 
 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]
   
 
 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]
   
 
 Merge:
 - one with change to an unrelated file
-- one deleting and recreating the change
+- 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]
   
 
 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]
   
 
 Merge:
 - one with change to an unrelated file
 - one deleting and recreating the change
 
   $ 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]
   
 
 Note:
-| In this case, the merge get conflicting information since each side have a
-| different way to reach 'f'.
+| 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.
 
 final summary
 
   $ hg update null --quiet
   $ hg log -G
   o    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    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  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  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]
   
 
 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, 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
+| 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 recorded copy is different depending of where we started the merge from since
+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
 
-This second b004912a8510032a0350a74daa2803dadfb00e12 seems wrong. We should record the merge
+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
 
+(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]
   
 
-(That output seems wrong, if we had opportunity to record the merge, we should
-probably have recorded the merge).
+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 re-adding the file afterward
 ---------------------------------------------------
 
 - one with change to an unrelated file
 - one deleting and recreating the change
 
   $ 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