--- a/hgext3rd/evolve/stablerange.py	Sun Nov 26 11:58:35 2017 -0500
+++ b/hgext3rd/evolve/stablerange.py	Sun Dec 10 01:06:16 2017 +0100
@@ -76,6 +76,7 @@
 _stablerangemethodmap = {
     'branchpoint': lambda repo: repo.stablerange,
     'basic-branchpoint': lambda repo: stablerangebasic(),
+    'basic-mergepoint': lambda repo: stablerangedummy_mergepoint(),
 }
 
 @eh.command(
@@ -284,6 +285,13 @@
         assert initialrevs == subrangerevs
         return result
 
+class stablerangedummy_mergepoint(stablerangebasic):
+    """a very dummy implementation of stablerange use 'mergepoint' sorting
+    """
+
+    def _sortfunction(self, repo, headrev):
+        return stablesort.stablesort_mergepoint_head_basic(repo, [headrev])
+
 class stablerange(abstractstablerange):
 
     def __init__(self, lrusize=2000):

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-stablerange-branchpoint.t	Sun Dec 10 01:06:16 2017 +0100
@@ -0,0 +1,731 @@
+Test for stable ordering capabilities
+=====================================
+
+  $ . $TESTDIR/testlib/pythonpath.sh
+
+  $ cat << EOF >> $HGRCPATH
+  > [extensions]
+  > hgext3rd.evolve =
+  > [ui]
+  > logtemplate = "{rev} {node|short} {desc} {tags}\n"
+  > [defaults]
+  > debugstablerange = --method branchpoint
+  > EOF
+
+Simple linear test
+==================
+
+  $ hg init repo_linear
+  $ cd repo_linear
+  $ hg debugbuilddag '.+6'
+  $ hg debugdepth -r 'all()'
+  1ea73414a91b 1
+  66f7d451a68b 2
+  01241442b3c2 3
+  2dc09a01254d 4
+  bebd167eb94d 5
+  c8d03c1b5e94 6
+  f69452c5b1af 7
+  $ hg debugstablerange --verify --verbose --subranges --rev 1
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 1 > 1.range
+
+bigger subset reuse most of the previous one
+
+  $ hg debugstablerange --verify --verbose --subranges --rev 4
+  bebd167eb94d-0 (4, 5, 5) [complete] - 2dc09a01254d-0 (3, 4, 4), bebd167eb94d-4 (4, 5, 1)
+  2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  01241442b3c2-2 (2, 3, 1) [leaf] - 
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  2dc09a01254d-3 (3, 4, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  bebd167eb94d-4 (4, 5, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 4 > 4.range
+  $ diff -u 1.range 4.range
+  --- 1.range	* (glob)
+  +++ 4.range	* (glob)
+  @@ -1,3 +1,9 @@
+  +bebd167eb94d-0 (4, 5, 5) [complete] - 2dc09a01254d-0 (3, 4, 4), bebd167eb94d-4 (4, 5, 1)
+  +2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  +2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+   66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  +01241442b3c2-2 (2, 3, 1) [leaf] - 
+   1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  +2dc09a01254d-3 (3, 4, 1) [leaf] - 
+   66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  +bebd167eb94d-4 (4, 5, 1) [leaf] - 
+  [1]
+
+Using a range not ending on 2**N boundary
+we fall back on 2**N as much as possible
+
+  $ hg debugstablerange --verify --verbose --subranges --rev 5
+  c8d03c1b5e94-0 (5, 6, 6) [complete] - 2dc09a01254d-0 (3, 4, 4), c8d03c1b5e94-4 (5, 6, 2)
+  2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  c8d03c1b5e94-4 (5, 6, 2) [complete] - bebd167eb94d-4 (4, 5, 1), c8d03c1b5e94-5 (5, 6, 1)
+  01241442b3c2-2 (2, 3, 1) [leaf] - 
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  2dc09a01254d-3 (3, 4, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  bebd167eb94d-4 (4, 5, 1) [leaf] - 
+  c8d03c1b5e94-5 (5, 6, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 5 > 5.range
+  $ diff -u 4.range 5.range
+  --- 4.range	* (glob)
+  +++ 5.range	* (glob)
+  @@ -1,9 +1,11 @@
+  -bebd167eb94d-0 (4, 5, 5) [complete] - 2dc09a01254d-0 (3, 4, 4), bebd167eb94d-4 (4, 5, 1)
+  +c8d03c1b5e94-0 (5, 6, 6) [complete] - 2dc09a01254d-0 (3, 4, 4), c8d03c1b5e94-4 (5, 6, 2)
+   2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+   2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+   66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  +c8d03c1b5e94-4 (5, 6, 2) [complete] - bebd167eb94d-4 (4, 5, 1), c8d03c1b5e94-5 (5, 6, 1)
+   01241442b3c2-2 (2, 3, 1) [leaf] - 
+   1ea73414a91b-0 (0, 1, 1) [leaf] - 
+   2dc09a01254d-3 (3, 4, 1) [leaf] - 
+   66f7d451a68b-1 (1, 2, 1) [leaf] - 
+   bebd167eb94d-4 (4, 5, 1) [leaf] - 
+  +c8d03c1b5e94-5 (5, 6, 1) [leaf] - 
+  [1]
+
+Even two unperfect range overlap a lot
+
+  $ hg debugstablerange --verify --verbose --subranges --rev tip
+  f69452c5b1af-0 (6, 7, 7) [complete] - 2dc09a01254d-0 (3, 4, 4), f69452c5b1af-4 (6, 7, 3)
+  2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  f69452c5b1af-4 (6, 7, 3) [complete] - c8d03c1b5e94-4 (5, 6, 2), f69452c5b1af-6 (6, 7, 1)
+  2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  c8d03c1b5e94-4 (5, 6, 2) [complete] - bebd167eb94d-4 (4, 5, 1), c8d03c1b5e94-5 (5, 6, 1)
+  01241442b3c2-2 (2, 3, 1) [leaf] - 
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  2dc09a01254d-3 (3, 4, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  bebd167eb94d-4 (4, 5, 1) [leaf] - 
+  c8d03c1b5e94-5 (5, 6, 1) [leaf] - 
+  f69452c5b1af-6 (6, 7, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev tip > tip.range
+  $ diff -u 5.range tip.range
+  --- 5.range	* (glob)
+  +++ tip.range	* (glob)
+  @@ -1,5 +1,6 @@
+  -c8d03c1b5e94-0 (5, 6, 6) [complete] - 2dc09a01254d-0 (3, 4, 4), c8d03c1b5e94-4 (5, 6, 2)
+  +f69452c5b1af-0 (6, 7, 7) [complete] - 2dc09a01254d-0 (3, 4, 4), f69452c5b1af-4 (6, 7, 3)
+   2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  +f69452c5b1af-4 (6, 7, 3) [complete] - c8d03c1b5e94-4 (5, 6, 2), f69452c5b1af-6 (6, 7, 1)
+   2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+   66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+   c8d03c1b5e94-4 (5, 6, 2) [complete] - bebd167eb94d-4 (4, 5, 1), c8d03c1b5e94-5 (5, 6, 1)
+  @@ -9,3 +10,4 @@
+   66f7d451a68b-1 (1, 2, 1) [leaf] - 
+   bebd167eb94d-4 (4, 5, 1) [leaf] - 
+   c8d03c1b5e94-5 (5, 6, 1) [leaf] - 
+  +f69452c5b1af-6 (6, 7, 1) [leaf] - 
+  [1]
+
+  $ cd ..
+
+Case with merge
+===============
+
+Simple case: branching is on a boundary
+--------------------------------------------
+
+  $ hg init repo_merge_split_on_boundary
+  $ cd repo_merge_split_on_boundary
+  $ hg debugbuilddag '.:base
+  > +3:left
+  > <base+3:right
+  > <left/right:merge
+  > +2:head
+  > '
+  $ hg log -G
+  o  9 0338daf18215 r9 head tip
+  |
+  o  8 71b32fcf3f71 r8
+  |
+  o    7 5f18015f9110 r7 merge
+  |\
+  | o  6 a2f58e9c1e56 r6 right
+  | |
+  | o  5 3a367db1fabc r5
+  | |
+  | o  4 e7bd5218ca15 r4
+  | |
+  o |  3 2dc09a01254d r3 left
+  | |
+  o |  2 01241442b3c2 r2
+  | |
+  o |  1 66f7d451a68b r1
+  |/
+  o  0 1ea73414a91b r0 base
+  
+  $ hg debugdepth -r 'all()'
+  1ea73414a91b 1
+  66f7d451a68b 2
+  01241442b3c2 3
+  2dc09a01254d 4
+  e7bd5218ca15 2
+  3a367db1fabc 3
+  a2f58e9c1e56 4
+  5f18015f9110 8
+  71b32fcf3f71 9
+  0338daf18215 10
+
+Each of the linear branch reuse range internally
+
+(left branch)
+
+  $ hg debugstablerange --verify --verbose --subranges --rev 'left~2'
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 'left~2' > left-2.range
+  $ hg debugstablerange --verify --verbose --subranges --rev left
+  2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  01241442b3c2-2 (2, 3, 1) [leaf] - 
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  2dc09a01254d-3 (3, 4, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 'left' > left.range
+  $ diff -u left-2.range left.range
+  --- left-2.range	* (glob)
+  +++ left.range	* (glob)
+  @@ -1,3 +1,7 @@
+  +2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  +2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+   66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  +01241442b3c2-2 (2, 3, 1) [leaf] - 
+   1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  +2dc09a01254d-3 (3, 4, 1) [leaf] - 
+   66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  [1]
+
+(right branch)
+
+  $ hg debugstablerange --verify --verbose --subranges --rev right~2
+  e7bd5218ca15-0 (4, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), e7bd5218ca15-1 (4, 2, 1)
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  e7bd5218ca15-1 (4, 2, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 'right~2' > right-2.range
+  $ hg debugstablerange --verify --verbose --subranges --rev right
+  a2f58e9c1e56-0 (6, 4, 4) [complete] - e7bd5218ca15-0 (4, 2, 2), a2f58e9c1e56-2 (6, 4, 2)
+  a2f58e9c1e56-2 (6, 4, 2) [complete] - 3a367db1fabc-2 (5, 3, 1), a2f58e9c1e56-3 (6, 4, 1)
+  e7bd5218ca15-0 (4, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), e7bd5218ca15-1 (4, 2, 1)
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  3a367db1fabc-2 (5, 3, 1) [leaf] - 
+  a2f58e9c1e56-3 (6, 4, 1) [leaf] - 
+  e7bd5218ca15-1 (4, 2, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 'right' > right.range
+  $ diff -u right-2.range right.range
+  --- right-2.range	* (glob)
+  +++ right.range	* (glob)
+  @@ -1,3 +1,7 @@
+  +a2f58e9c1e56-0 (6, 4, 4) [complete] - e7bd5218ca15-0 (4, 2, 2), a2f58e9c1e56-2 (6, 4, 2)
+  +a2f58e9c1e56-2 (6, 4, 2) [complete] - 3a367db1fabc-2 (5, 3, 1), a2f58e9c1e56-3 (6, 4, 1)
+   e7bd5218ca15-0 (4, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), e7bd5218ca15-1 (4, 2, 1)
+   1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  +3a367db1fabc-2 (5, 3, 1) [leaf] - 
+  +a2f58e9c1e56-3 (6, 4, 1) [leaf] - 
+   e7bd5218ca15-1 (4, 2, 1) [leaf] - 
+  [1]
+
+The merge reuse as much of the slicing created for one of the branch
+
+  $ hg debugstablerange --verify --verbose --subranges --rev merge
+  5f18015f9110-0 (7, 8, 8) [complete] - 2dc09a01254d-0 (3, 4, 4), 5f18015f9110-4 (7, 8, 4)
+  2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  5f18015f9110-4 (7, 8, 4) [complete] - 3a367db1fabc-1 (5, 3, 2), 5f18015f9110-6 (7, 8, 2)
+  2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+  3a367db1fabc-1 (5, 3, 2) [complete] - e7bd5218ca15-1 (4, 2, 1), 3a367db1fabc-2 (5, 3, 1)
+  5f18015f9110-6 (7, 8, 2) [complete] - a2f58e9c1e56-3 (6, 4, 1), 5f18015f9110-7 (7, 8, 1)
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  01241442b3c2-2 (2, 3, 1) [leaf] - 
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  2dc09a01254d-3 (3, 4, 1) [leaf] - 
+  3a367db1fabc-2 (5, 3, 1) [leaf] - 
+  5f18015f9110-7 (7, 8, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  a2f58e9c1e56-3 (6, 4, 1) [leaf] - 
+  e7bd5218ca15-1 (4, 2, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 'merge' > merge.range
+  $ diff -u left.range merge.range
+  --- left.range	* (glob)
+  +++ merge.range	* (glob)
+  @@ -1,7 +1,15 @@
+  +5f18015f9110-0 (7, 8, 8) [complete] - 2dc09a01254d-0 (3, 4, 4), 5f18015f9110-4 (7, 8, 4)
+   2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  +5f18015f9110-4 (7, 8, 4) [complete] - 3a367db1fabc-1 (5, 3, 2), 5f18015f9110-6 (7, 8, 2)
+   2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+  +3a367db1fabc-1 (5, 3, 2) [complete] - e7bd5218ca15-1 (4, 2, 1), 3a367db1fabc-2 (5, 3, 1)
+  +5f18015f9110-6 (7, 8, 2) [complete] - a2f58e9c1e56-3 (6, 4, 1), 5f18015f9110-7 (7, 8, 1)
+   66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+   01241442b3c2-2 (2, 3, 1) [leaf] - 
+   1ea73414a91b-0 (0, 1, 1) [leaf] - 
+   2dc09a01254d-3 (3, 4, 1) [leaf] - 
+  +3a367db1fabc-2 (5, 3, 1) [leaf] - 
+  +5f18015f9110-7 (7, 8, 1) [leaf] - 
+   66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  +a2f58e9c1e56-3 (6, 4, 1) [leaf] - 
+  +e7bd5218ca15-1 (4, 2, 1) [leaf] - 
+  [1]
+  $ diff -u right.range merge.range
+  --- right.range	* (glob)
+  +++ merge.range	* (glob)
+  @@ -1,7 +1,15 @@
+  -a2f58e9c1e56-0 (6, 4, 4) [complete] - e7bd5218ca15-0 (4, 2, 2), a2f58e9c1e56-2 (6, 4, 2)
+  -a2f58e9c1e56-2 (6, 4, 2) [complete] - 3a367db1fabc-2 (5, 3, 1), a2f58e9c1e56-3 (6, 4, 1)
+  -e7bd5218ca15-0 (4, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), e7bd5218ca15-1 (4, 2, 1)
+  +5f18015f9110-0 (7, 8, 8) [complete] - 2dc09a01254d-0 (3, 4, 4), 5f18015f9110-4 (7, 8, 4)
+  +2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  +5f18015f9110-4 (7, 8, 4) [complete] - 3a367db1fabc-1 (5, 3, 2), 5f18015f9110-6 (7, 8, 2)
+  +2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+  +3a367db1fabc-1 (5, 3, 2) [complete] - e7bd5218ca15-1 (4, 2, 1), 3a367db1fabc-2 (5, 3, 1)
+  +5f18015f9110-6 (7, 8, 2) [complete] - a2f58e9c1e56-3 (6, 4, 1), 5f18015f9110-7 (7, 8, 1)
+  +66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  +01241442b3c2-2 (2, 3, 1) [leaf] - 
+   1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  +2dc09a01254d-3 (3, 4, 1) [leaf] - 
+   3a367db1fabc-2 (5, 3, 1) [leaf] - 
+  +5f18015f9110-7 (7, 8, 1) [leaf] - 
+  +66f7d451a68b-1 (1, 2, 1) [leaf] - 
+   a2f58e9c1e56-3 (6, 4, 1) [leaf] - 
+   e7bd5218ca15-1 (4, 2, 1) [leaf] - 
+  [1]
+  $ cd ..
+
+slice create multiple heads
+---------------------------
+
+  $ hg init repo_merge_split_heads
+  $ cd repo_merge_split_heads
+  $ hg debugbuilddag '.:base
+  > +4:left
+  > <base+5:right
+  > <left/right:merge
+  > +2:head
+  > '
+  $ hg debugbuilddag '.:base
+  > +3:left
+  > <base+3:right
+  > <left/right:merge
+  > +2:head
+  > '
+  abort: repository is not empty
+  [255]
+  $ hg log -G
+  o  12 e6b8d5b46647 r12 head tip
+  |
+  o  11 485383494a89 r11
+  |
+  o    10 8aca7f8c9bd2 r10 merge
+  |\
+  | o  9 f4b7da68b467 r9 right
+  | |
+  | o  8 857477a9aebb r8
+  | |
+  | o  7 42b07e8da27d r7
+  | |
+  | o  6 b9bc20507e0b r6
+  | |
+  | o  5 de561312eff4 r5
+  | |
+  o |  4 bebd167eb94d r4 left
+  | |
+  o |  3 2dc09a01254d r3
+  | |
+  o |  2 01241442b3c2 r2
+  | |
+  o |  1 66f7d451a68b r1
+  |/
+  o  0 1ea73414a91b r0 base
+  
+  $ hg debugdepth -r 'all()'
+  1ea73414a91b 1
+  66f7d451a68b 2
+  01241442b3c2 3
+  2dc09a01254d 4
+  bebd167eb94d 5
+  de561312eff4 2
+  b9bc20507e0b 3
+  42b07e8da27d 4
+  857477a9aebb 5
+  f4b7da68b467 6
+  8aca7f8c9bd2 11
+  485383494a89 12
+  e6b8d5b46647 13
+
+Each of the linear branch reuse range internally
+
+(left branch)
+
+  $ hg debugstablerange --verify --verbose --subranges --rev 'left~2'
+  01241442b3c2-0 (2, 3, 3) [complete] - 66f7d451a68b-0 (1, 2, 2), 01241442b3c2-2 (2, 3, 1)
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  01241442b3c2-2 (2, 3, 1) [leaf] - 
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 'left~2' > left-2.range
+  $ hg debugstablerange --verify --verbose --subranges --rev left
+  bebd167eb94d-0 (4, 5, 5) [complete] - 2dc09a01254d-0 (3, 4, 4), bebd167eb94d-4 (4, 5, 1)
+  2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  01241442b3c2-2 (2, 3, 1) [leaf] - 
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  2dc09a01254d-3 (3, 4, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  bebd167eb94d-4 (4, 5, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 'left' > left.range
+  $ diff -u left-2.range left.range
+  --- left-2.range	* (glob)
+  +++ left.range	* (glob)
+  @@ -1,5 +1,9 @@
+  -01241442b3c2-0 (2, 3, 3) [complete] - 66f7d451a68b-0 (1, 2, 2), 01241442b3c2-2 (2, 3, 1)
+  +bebd167eb94d-0 (4, 5, 5) [complete] - 2dc09a01254d-0 (3, 4, 4), bebd167eb94d-4 (4, 5, 1)
+  +2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  +2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+   66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+   01241442b3c2-2 (2, 3, 1) [leaf] - 
+   1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  +2dc09a01254d-3 (3, 4, 1) [leaf] - 
+   66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  +bebd167eb94d-4 (4, 5, 1) [leaf] - 
+  [1]
+
+(right branch)
+
+  $ hg debugstablerange --verify --verbose --subranges --rev right~2
+  42b07e8da27d-0 (7, 4, 4) [complete] - de561312eff4-0 (5, 2, 2), 42b07e8da27d-2 (7, 4, 2)
+  42b07e8da27d-2 (7, 4, 2) [complete] - b9bc20507e0b-2 (6, 3, 1), 42b07e8da27d-3 (7, 4, 1)
+  de561312eff4-0 (5, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), de561312eff4-1 (5, 2, 1)
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  42b07e8da27d-3 (7, 4, 1) [leaf] - 
+  b9bc20507e0b-2 (6, 3, 1) [leaf] - 
+  de561312eff4-1 (5, 2, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 'right~2' > right-2.range
+  $ hg debugstablerange --verify --verbose --subranges --rev right
+  f4b7da68b467-0 (9, 6, 6) [complete] - 42b07e8da27d-0 (7, 4, 4), f4b7da68b467-4 (9, 6, 2)
+  42b07e8da27d-0 (7, 4, 4) [complete] - de561312eff4-0 (5, 2, 2), 42b07e8da27d-2 (7, 4, 2)
+  42b07e8da27d-2 (7, 4, 2) [complete] - b9bc20507e0b-2 (6, 3, 1), 42b07e8da27d-3 (7, 4, 1)
+  de561312eff4-0 (5, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), de561312eff4-1 (5, 2, 1)
+  f4b7da68b467-4 (9, 6, 2) [complete] - 857477a9aebb-4 (8, 5, 1), f4b7da68b467-5 (9, 6, 1)
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  42b07e8da27d-3 (7, 4, 1) [leaf] - 
+  857477a9aebb-4 (8, 5, 1) [leaf] - 
+  b9bc20507e0b-2 (6, 3, 1) [leaf] - 
+  de561312eff4-1 (5, 2, 1) [leaf] - 
+  f4b7da68b467-5 (9, 6, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 'right' > right.range
+  $ diff -u right-2.range right.range
+  --- right-2.range	* (glob)
+  +++ right.range	* (glob)
+  @@ -1,7 +1,11 @@
+  +f4b7da68b467-0 (9, 6, 6) [complete] - 42b07e8da27d-0 (7, 4, 4), f4b7da68b467-4 (9, 6, 2)
+   42b07e8da27d-0 (7, 4, 4) [complete] - de561312eff4-0 (5, 2, 2), 42b07e8da27d-2 (7, 4, 2)
+   42b07e8da27d-2 (7, 4, 2) [complete] - b9bc20507e0b-2 (6, 3, 1), 42b07e8da27d-3 (7, 4, 1)
+   de561312eff4-0 (5, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), de561312eff4-1 (5, 2, 1)
+  +f4b7da68b467-4 (9, 6, 2) [complete] - 857477a9aebb-4 (8, 5, 1), f4b7da68b467-5 (9, 6, 1)
+   1ea73414a91b-0 (0, 1, 1) [leaf] - 
+   42b07e8da27d-3 (7, 4, 1) [leaf] - 
+  +857477a9aebb-4 (8, 5, 1) [leaf] - 
+   b9bc20507e0b-2 (6, 3, 1) [leaf] - 
+   de561312eff4-1 (5, 2, 1) [leaf] - 
+  +f4b7da68b467-5 (9, 6, 1) [leaf] - 
+  [1]
+
+In this case, the bottom of the split will have multiple heads,
+
+So we'll create more than 1 subrange out of it.
+
+We are still able to reuse one of the branch however
+
+  $ hg debugstablerange --verify --verbose --subranges --rev merge
+  8aca7f8c9bd2-0 (10, 11, 11) [complete] - bebd167eb94d-0 (4, 5, 5), 42b07e8da27d-1 (7, 4, 3), 8aca7f8c9bd2-8 (10, 11, 3)
+  bebd167eb94d-0 (4, 5, 5) [complete] - 2dc09a01254d-0 (3, 4, 4), bebd167eb94d-4 (4, 5, 1)
+  2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  42b07e8da27d-1 (7, 4, 3) [complete] - de561312eff4-1 (5, 2, 1), 42b07e8da27d-2 (7, 4, 2)
+  8aca7f8c9bd2-8 (10, 11, 3) [complete] - f4b7da68b467-4 (9, 6, 2), 8aca7f8c9bd2-10 (10, 11, 1)
+  2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+  42b07e8da27d-2 (7, 4, 2) [complete] - b9bc20507e0b-2 (6, 3, 1), 42b07e8da27d-3 (7, 4, 1)
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  f4b7da68b467-4 (9, 6, 2) [complete] - 857477a9aebb-4 (8, 5, 1), f4b7da68b467-5 (9, 6, 1)
+  01241442b3c2-2 (2, 3, 1) [leaf] - 
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  2dc09a01254d-3 (3, 4, 1) [leaf] - 
+  42b07e8da27d-3 (7, 4, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  857477a9aebb-4 (8, 5, 1) [leaf] - 
+  8aca7f8c9bd2-10 (10, 11, 1) [leaf] - 
+  b9bc20507e0b-2 (6, 3, 1) [leaf] - 
+  bebd167eb94d-4 (4, 5, 1) [leaf] - 
+  de561312eff4-1 (5, 2, 1) [leaf] - 
+  f4b7da68b467-5 (9, 6, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 'merge' > merge.range
+  $ diff -u left.range merge.range
+  --- left.range	* (glob)
+  +++ merge.range	* (glob)
+  @@ -1,9 +1,20 @@
+  +8aca7f8c9bd2-0 (10, 11, 11) [complete] - bebd167eb94d-0 (4, 5, 5), 42b07e8da27d-1 (7, 4, 3), 8aca7f8c9bd2-8 (10, 11, 3)
+   bebd167eb94d-0 (4, 5, 5) [complete] - 2dc09a01254d-0 (3, 4, 4), bebd167eb94d-4 (4, 5, 1)
+   2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  +42b07e8da27d-1 (7, 4, 3) [complete] - de561312eff4-1 (5, 2, 1), 42b07e8da27d-2 (7, 4, 2)
+  +8aca7f8c9bd2-8 (10, 11, 3) [complete] - f4b7da68b467-4 (9, 6, 2), 8aca7f8c9bd2-10 (10, 11, 1)
+   2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+  +42b07e8da27d-2 (7, 4, 2) [complete] - b9bc20507e0b-2 (6, 3, 1), 42b07e8da27d-3 (7, 4, 1)
+   66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  +f4b7da68b467-4 (9, 6, 2) [complete] - 857477a9aebb-4 (8, 5, 1), f4b7da68b467-5 (9, 6, 1)
+   01241442b3c2-2 (2, 3, 1) [leaf] - 
+   1ea73414a91b-0 (0, 1, 1) [leaf] - 
+   2dc09a01254d-3 (3, 4, 1) [leaf] - 
+  +42b07e8da27d-3 (7, 4, 1) [leaf] - 
+   66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  +857477a9aebb-4 (8, 5, 1) [leaf] - 
+  +8aca7f8c9bd2-10 (10, 11, 1) [leaf] - 
+  +b9bc20507e0b-2 (6, 3, 1) [leaf] - 
+   bebd167eb94d-4 (4, 5, 1) [leaf] - 
+  +de561312eff4-1 (5, 2, 1) [leaf] - 
+  +f4b7da68b467-5 (9, 6, 1) [leaf] - 
+  [1]
+  $ diff -u right.range merge.range
+  --- right.range	* (glob)
+  +++ merge.range	* (glob)
+  @@ -1,11 +1,20 @@
+  -f4b7da68b467-0 (9, 6, 6) [complete] - 42b07e8da27d-0 (7, 4, 4), f4b7da68b467-4 (9, 6, 2)
+  -42b07e8da27d-0 (7, 4, 4) [complete] - de561312eff4-0 (5, 2, 2), 42b07e8da27d-2 (7, 4, 2)
+  +8aca7f8c9bd2-0 (10, 11, 11) [complete] - bebd167eb94d-0 (4, 5, 5), 42b07e8da27d-1 (7, 4, 3), 8aca7f8c9bd2-8 (10, 11, 3)
+  +bebd167eb94d-0 (4, 5, 5) [complete] - 2dc09a01254d-0 (3, 4, 4), bebd167eb94d-4 (4, 5, 1)
+  +2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  +42b07e8da27d-1 (7, 4, 3) [complete] - de561312eff4-1 (5, 2, 1), 42b07e8da27d-2 (7, 4, 2)
+  +8aca7f8c9bd2-8 (10, 11, 3) [complete] - f4b7da68b467-4 (9, 6, 2), 8aca7f8c9bd2-10 (10, 11, 1)
+  +2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+   42b07e8da27d-2 (7, 4, 2) [complete] - b9bc20507e0b-2 (6, 3, 1), 42b07e8da27d-3 (7, 4, 1)
+  -de561312eff4-0 (5, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), de561312eff4-1 (5, 2, 1)
+  +66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+   f4b7da68b467-4 (9, 6, 2) [complete] - 857477a9aebb-4 (8, 5, 1), f4b7da68b467-5 (9, 6, 1)
+  +01241442b3c2-2 (2, 3, 1) [leaf] - 
+   1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  +2dc09a01254d-3 (3, 4, 1) [leaf] - 
+   42b07e8da27d-3 (7, 4, 1) [leaf] - 
+  +66f7d451a68b-1 (1, 2, 1) [leaf] - 
+   857477a9aebb-4 (8, 5, 1) [leaf] - 
+  +8aca7f8c9bd2-10 (10, 11, 1) [leaf] - 
+   b9bc20507e0b-2 (6, 3, 1) [leaf] - 
+  +bebd167eb94d-4 (4, 5, 1) [leaf] - 
+   de561312eff4-1 (5, 2, 1) [leaf] - 
+   f4b7da68b467-5 (9, 6, 1) [leaf] - 
+  [1]
+
+Range above the merge, reuse subrange from the merge
+
+  $ hg debugstablerange --verify --verbose --subranges --rev tip
+  e6b8d5b46647-0 (12, 13, 13) [complete] - bebd167eb94d-0 (4, 5, 5), 42b07e8da27d-1 (7, 4, 3), e6b8d5b46647-8 (12, 13, 5)
+  bebd167eb94d-0 (4, 5, 5) [complete] - 2dc09a01254d-0 (3, 4, 4), bebd167eb94d-4 (4, 5, 1)
+  e6b8d5b46647-8 (12, 13, 5) [complete] - 485383494a89-8 (11, 12, 4), e6b8d5b46647-12 (12, 13, 1)
+  2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  485383494a89-8 (11, 12, 4) [complete] - f4b7da68b467-4 (9, 6, 2), 485383494a89-10 (11, 12, 2)
+  42b07e8da27d-1 (7, 4, 3) [complete] - de561312eff4-1 (5, 2, 1), 42b07e8da27d-2 (7, 4, 2)
+  2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+  42b07e8da27d-2 (7, 4, 2) [complete] - b9bc20507e0b-2 (6, 3, 1), 42b07e8da27d-3 (7, 4, 1)
+  485383494a89-10 (11, 12, 2) [complete] - 8aca7f8c9bd2-10 (10, 11, 1), 485383494a89-11 (11, 12, 1)
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  f4b7da68b467-4 (9, 6, 2) [complete] - 857477a9aebb-4 (8, 5, 1), f4b7da68b467-5 (9, 6, 1)
+  01241442b3c2-2 (2, 3, 1) [leaf] - 
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  2dc09a01254d-3 (3, 4, 1) [leaf] - 
+  42b07e8da27d-3 (7, 4, 1) [leaf] - 
+  485383494a89-11 (11, 12, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  857477a9aebb-4 (8, 5, 1) [leaf] - 
+  8aca7f8c9bd2-10 (10, 11, 1) [leaf] - 
+  b9bc20507e0b-2 (6, 3, 1) [leaf] - 
+  bebd167eb94d-4 (4, 5, 1) [leaf] - 
+  de561312eff4-1 (5, 2, 1) [leaf] - 
+  e6b8d5b46647-12 (12, 13, 1) [leaf] - 
+  f4b7da68b467-5 (9, 6, 1) [leaf] - 
+  $ hg debugstablerange --verify --verbose --subranges --rev 'tip' > tip.range
+  $ diff -u merge.range tip.range
+  --- merge.range	* (glob)
+  +++ tip.range	* (glob)
+  @@ -1,20 +1,24 @@
+  -8aca7f8c9bd2-0 (10, 11, 11) [complete] - bebd167eb94d-0 (4, 5, 5), 42b07e8da27d-1 (7, 4, 3), 8aca7f8c9bd2-8 (10, 11, 3)
+  +e6b8d5b46647-0 (12, 13, 13) [complete] - bebd167eb94d-0 (4, 5, 5), 42b07e8da27d-1 (7, 4, 3), e6b8d5b46647-8 (12, 13, 5)
+   bebd167eb94d-0 (4, 5, 5) [complete] - 2dc09a01254d-0 (3, 4, 4), bebd167eb94d-4 (4, 5, 1)
+  +e6b8d5b46647-8 (12, 13, 5) [complete] - 485383494a89-8 (11, 12, 4), e6b8d5b46647-12 (12, 13, 1)
+   2dc09a01254d-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2dc09a01254d-2 (3, 4, 2)
+  +485383494a89-8 (11, 12, 4) [complete] - f4b7da68b467-4 (9, 6, 2), 485383494a89-10 (11, 12, 2)
+   42b07e8da27d-1 (7, 4, 3) [complete] - de561312eff4-1 (5, 2, 1), 42b07e8da27d-2 (7, 4, 2)
+  -8aca7f8c9bd2-8 (10, 11, 3) [complete] - f4b7da68b467-4 (9, 6, 2), 8aca7f8c9bd2-10 (10, 11, 1)
+   2dc09a01254d-2 (3, 4, 2) [complete] - 01241442b3c2-2 (2, 3, 1), 2dc09a01254d-3 (3, 4, 1)
+   42b07e8da27d-2 (7, 4, 2) [complete] - b9bc20507e0b-2 (6, 3, 1), 42b07e8da27d-3 (7, 4, 1)
+  +485383494a89-10 (11, 12, 2) [complete] - 8aca7f8c9bd2-10 (10, 11, 1), 485383494a89-11 (11, 12, 1)
+   66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+   f4b7da68b467-4 (9, 6, 2) [complete] - 857477a9aebb-4 (8, 5, 1), f4b7da68b467-5 (9, 6, 1)
+   01241442b3c2-2 (2, 3, 1) [leaf] - 
+   1ea73414a91b-0 (0, 1, 1) [leaf] - 
+   2dc09a01254d-3 (3, 4, 1) [leaf] - 
+   42b07e8da27d-3 (7, 4, 1) [leaf] - 
+  +485383494a89-11 (11, 12, 1) [leaf] - 
+   66f7d451a68b-1 (1, 2, 1) [leaf] - 
+   857477a9aebb-4 (8, 5, 1) [leaf] - 
+   8aca7f8c9bd2-10 (10, 11, 1) [leaf] - 
+   b9bc20507e0b-2 (6, 3, 1) [leaf] - 
+   bebd167eb94d-4 (4, 5, 1) [leaf] - 
+   de561312eff4-1 (5, 2, 1) [leaf] - 
+  +e6b8d5b46647-12 (12, 13, 1) [leaf] - 
+   f4b7da68b467-5 (9, 6, 1) [leaf] - 
+  [1]
+
+  $ cd ..
+
+Tests range with criss cross merge in the graph
+===============================================
+
+  $ hg init repo_criss_cross
+  $ cd repo_criss_cross
+  $ hg debugbuilddag '
+  > ..:g   # 2 nodes, tagged "g"
+  > <2.:h   # another node base one -2 -> 0, tagged "h"
+  > *1/2:m # merge -1 and -2 (1, 2), tagged "m"
+  > <2+2:i # 2 nodes based on -2, tag head as "i"
+  > .:c    # 1 node tagged "c"
+  > <m+3:a # 3 nodes base on the "m" tag
+  > <2.:b  # 1 node based on -2; tagged "b"
+  > <m+2:d # 2 nodes from "m" tagged "d"
+  > <2.:e  # 1 node based on -2, tagged "e"
+  > <m+1:f # 1 node based on "m" tagged "f"
+  > <i/f   # merge "i" and "f"
+  > '
+  $ hg log -G
+  o    15 1d8d22637c2d r15 tip
+  |\
+  | o  14 43227190fef8 r14 f
+  | |
+  | | o  13 b4594d867745 r13 e
+  | | |
+  | | | o  12 e46a4836065c r12 d
+  | | |/
+  | | o  11 bab5d5bf48bd r11
+  | |/
+  | | o  10 ff43616e5d0f r10 b
+  | | |
+  | | | o  9 dcbb326fdec2 r9 a
+  | | |/
+  | | o  8 d62d843c9a01 r8
+  | | |
+  | | o  7 e7d9710d9fc6 r7
+  | |/
+  +---o  6 2702dd0c91e7 r6 c
+  | |
+  o |  5 f0f3ef9a6cd5 r5 i
+  | |
+  o |  4 4c748ffd1a46 r4
+  | |
+  | o  3 2b6d669947cd r3 m
+  |/|
+  o |  2 fa942426a6fd r2 h
+  | |
+  | o  1 66f7d451a68b r1 g
+  |/
+  o  0 1ea73414a91b r0
+  
+  $ hg debugdepth -r 'all()'
+  1ea73414a91b 1
+  66f7d451a68b 2
+  fa942426a6fd 2
+  2b6d669947cd 4
+  4c748ffd1a46 3
+  f0f3ef9a6cd5 4
+  2702dd0c91e7 5
+  e7d9710d9fc6 5
+  d62d843c9a01 6
+  dcbb326fdec2 7
+  ff43616e5d0f 7
+  bab5d5bf48bd 5
+  e46a4836065c 6
+  b4594d867745 6
+  43227190fef8 5
+  1d8d22637c2d 8
+  $ hg debugstablerange --verify --verbose --subranges --rev 'head()'
+  1d8d22637c2d-0 (15, 8, 8) [complete] - 2b6d669947cd-0 (3, 4, 4), 1d8d22637c2d-4 (15, 8, 4)
+  dcbb326fdec2-0 (9, 7, 7) [complete] - 2b6d669947cd-0 (3, 4, 4), dcbb326fdec2-4 (9, 7, 3)
+  ff43616e5d0f-0 (10, 7, 7) [complete] - 2b6d669947cd-0 (3, 4, 4), ff43616e5d0f-4 (10, 7, 3)
+  b4594d867745-0 (13, 6, 6) [complete] - 2b6d669947cd-0 (3, 4, 4), b4594d867745-4 (13, 6, 2)
+  e46a4836065c-0 (12, 6, 6) [complete] - 2b6d669947cd-0 (3, 4, 4), e46a4836065c-4 (12, 6, 2)
+  2702dd0c91e7-0 (6, 5, 5) [complete] - f0f3ef9a6cd5-0 (5, 4, 4), 2702dd0c91e7-4 (6, 5, 1)
+  1d8d22637c2d-4 (15, 8, 4) [complete] - 43227190fef8-4 (14, 5, 1), 4c748ffd1a46-2 (4, 3, 1), 1d8d22637c2d-6 (15, 8, 2)
+  2b6d669947cd-0 (3, 4, 4) [complete] - 66f7d451a68b-0 (1, 2, 2), 2b6d669947cd-2 (3, 4, 2)
+  f0f3ef9a6cd5-0 (5, 4, 4) [complete] - fa942426a6fd-0 (2, 2, 2), f0f3ef9a6cd5-2 (5, 4, 2)
+  dcbb326fdec2-4 (9, 7, 3) [complete] - d62d843c9a01-4 (8, 6, 2), dcbb326fdec2-6 (9, 7, 1)
+  ff43616e5d0f-4 (10, 7, 3) [complete] - d62d843c9a01-4 (8, 6, 2), ff43616e5d0f-6 (10, 7, 1)
+  1d8d22637c2d-6 (15, 8, 2) [complete] - f0f3ef9a6cd5-3 (5, 4, 1), 1d8d22637c2d-7 (15, 8, 1)
+  2b6d669947cd-2 (3, 4, 2) [complete] - fa942426a6fd-1 (2, 2, 1), 2b6d669947cd-3 (3, 4, 1)
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  b4594d867745-4 (13, 6, 2) [complete] - bab5d5bf48bd-4 (11, 5, 1), b4594d867745-5 (13, 6, 1)
+  d62d843c9a01-4 (8, 6, 2) [complete] - e7d9710d9fc6-4 (7, 5, 1), d62d843c9a01-5 (8, 6, 1)
+  e46a4836065c-4 (12, 6, 2) [complete] - bab5d5bf48bd-4 (11, 5, 1), e46a4836065c-5 (12, 6, 1)
+  f0f3ef9a6cd5-2 (5, 4, 2) [complete] - 4c748ffd1a46-2 (4, 3, 1), f0f3ef9a6cd5-3 (5, 4, 1)
+  fa942426a6fd-0 (2, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), fa942426a6fd-1 (2, 2, 1)
+  1d8d22637c2d-7 (15, 8, 1) [leaf] - 
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  2702dd0c91e7-4 (6, 5, 1) [leaf] - 
+  2b6d669947cd-3 (3, 4, 1) [leaf] - 
+  43227190fef8-4 (14, 5, 1) [leaf] - 
+  4c748ffd1a46-2 (4, 3, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  b4594d867745-5 (13, 6, 1) [leaf] - 
+  bab5d5bf48bd-4 (11, 5, 1) [leaf] - 
+  d62d843c9a01-5 (8, 6, 1) [leaf] - 
+  dcbb326fdec2-6 (9, 7, 1) [leaf] - 
+  e46a4836065c-5 (12, 6, 1) [leaf] - 
+  e7d9710d9fc6-4 (7, 5, 1) [leaf] - 
+  f0f3ef9a6cd5-3 (5, 4, 1) [leaf] - 
+  fa942426a6fd-1 (2, 2, 1) [leaf] - 
+  ff43616e5d0f-6 (10, 7, 1) [leaf] - 
+  $ cd ..
+
+Tests range where a toprange is rooted on a merge
+=================================================
+
+  $ hg init slice_on_merge
+  $ cd slice_on_merge
+  $ hg debugbuilddag '
+  > ..:a   # 2 nodes, tagged "a"
+  > <2..:b   # another branch with two node based on 0, tagged b
+  > *a/b:m # merge -1 and -2 (1, 2), tagged "m"
+  > '
+  $ hg log -G
+  o    4 f37e476fba9a r4 m tip
+  |\
+  | o  3 36315563e2fa r3 b
+  | |
+  | o  2 fa942426a6fd r2
+  | |
+  o |  1 66f7d451a68b r1 a
+  |/
+  o  0 1ea73414a91b r0
+  
+  $ hg debugdepth -r 'all()'
+  1ea73414a91b 1
+  66f7d451a68b 2
+  fa942426a6fd 2
+  36315563e2fa 3
+  f37e476fba9a 5
+  $ hg debugstablerange --verify --verbose --subranges --rev 'head()'
+  f37e476fba9a-0 (4, 5, 5) [complete] - 66f7d451a68b-0 (1, 2, 2), 36315563e2fa-1 (3, 3, 2), f37e476fba9a-4 (4, 5, 1)
+  36315563e2fa-1 (3, 3, 2) [complete] - fa942426a6fd-1 (2, 2, 1), 36315563e2fa-2 (3, 3, 1)
+  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  1ea73414a91b-0 (0, 1, 1) [leaf] - 
+  36315563e2fa-2 (3, 3, 1) [leaf] - 
+  66f7d451a68b-1 (1, 2, 1) [leaf] - 
+  f37e476fba9a-4 (4, 5, 1) [leaf] - 
+  fa942426a6fd-1 (2, 2, 1) [leaf] - 
+

--- a/tests/test-stablerange.t	Sun Nov 26 11:58:35 2017 -0500
+++ b/tests/test-stablerange.t	Sun Dec 10 01:06:16 2017 +0100
@@ -9,7 +9,7 @@
   > [ui]
   > logtemplate = "{rev} {node|short} {desc} {tags}\n"
   > [defaults]
-  > debugstablerange = --method branchpoint
+  > debugstablerange = --method basic-mergepoint
   > EOF
 
 Simple linear test
@@ -720,9 +720,9 @@
   36315563e2fa 3
   f37e476fba9a 5
   $ hg debugstablerange --verify --verbose --subranges --rev 'head()'
-  f37e476fba9a-0 (4, 5, 5) [complete] - 66f7d451a68b-0 (1, 2, 2), 36315563e2fa-1 (3, 3, 2), f37e476fba9a-4 (4, 5, 1)
-  36315563e2fa-1 (3, 3, 2) [complete] - fa942426a6fd-1 (2, 2, 1), 36315563e2fa-2 (3, 3, 1)
-  66f7d451a68b-0 (1, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), 66f7d451a68b-1 (1, 2, 1)
+  f37e476fba9a-0 (4, 5, 5) [complete] - 36315563e2fa-0 (3, 3, 3), 66f7d451a68b-1 (1, 2, 1), f37e476fba9a-4 (4, 5, 1)
+  36315563e2fa-0 (3, 3, 3) [complete] - fa942426a6fd-0 (2, 2, 2), 36315563e2fa-2 (3, 3, 1)
+  fa942426a6fd-0 (2, 2, 2) [complete] - 1ea73414a91b-0 (0, 1, 1), fa942426a6fd-1 (2, 2, 1)
   1ea73414a91b-0 (0, 1, 1) [leaf] - 
   36315563e2fa-2 (3, 3, 1) [leaf] - 
   66f7d451a68b-1 (1, 2, 1) [leaf] -