diff -r fc065ec30351 -r f9a850018daa tests/test-topic-stack.t
--- a/tests/test-topic-stack.t	Tue Aug 28 11:24:52 2018 +0200
+++ b/tests/test-topic-stack.t	Mon Sep 03 22:06:12 2018 +0200
@@ -60,8 +60,8 @@
   $ hg topic --list
   ### topic: other
   ### target: default (branch)
-  t2@ c_b (current)
-  t1: c_a
+  s2@ c_b (current)
+  s1: c_a
   $ hg phase --public 'topic("other")'
   active topic 'other' is now empty
 
@@ -74,7 +74,7 @@
   ### topic: other
   ### target: default (branch)
   (stack is empty)
-  t0^ c_b (base current)
+  s0^ c_b (base current)
 
   $ hg up foo
   switching to topic foo
@@ -90,19 +90,19 @@
   $ hg stack
   ### topic: foo
   ### target: default (branch)
-  t4@ c_f (current)
-  t3: c_e
-  t2: c_d
-  t1: c_c
-  t0^ c_b (base)
+  s4@ c_f (current)
+  s3: c_e
+  s2: c_d
+  s1: c_c
+  s0^ c_b (base)
   $ hg stack -v
   ### topic: foo
   ### target: default (branch)
-  t4(6559e6d93aea)@ c_f (current)
-  t3(0f9ac936c87d): c_e
-  t2(e629654d7050): c_d
-  t1(8522f9e3fee9): c_c
-  t0(ea705abc4f51)^ c_b (base)
+  s4(6559e6d93aea)@ c_f (current)
+  s3(0f9ac936c87d): c_e
+  s2(e629654d7050): c_d
+  s1(8522f9e3fee9): c_c
+  s0(ea705abc4f51)^ c_b (base)
   $ hg stack -Tjson | python -m json.tool
   [
       {
@@ -212,21 +212,21 @@
   $ hg stack
   ### topic: foo
   ### target: default (branch)
-  t4@ c_f (current)
-  t3: c_e
-  t2: c_d
-  t1: c_c
-  t0^ c_b (base)
+  s4@ c_f (current)
+  s3: c_e
+  s2: c_d
+  s1: c_c
+  s0^ c_b (base)
   $ hg topics --config ui.strict=true
    * foo (4 changesets)
   $ hg stack --config ui.strict=true
   ### topic: foo
   ### target: default (branch)
-  t4@ c_f (current)
-  t3: c_e
-  t2: c_d
-  t1: c_c
-  t0^ c_b (base)
+  s4@ c_f (current)
+  s3: c_e
+  s2: c_d
+  s1: c_c
+  s0^ c_b (base)
 
 error case, nothing to list
 
@@ -234,21 +234,24 @@
   $ hg stack
   ### target: default (branch)
   (stack is empty)
-  b0^ c_f (base current)
+  s0^ c_f (base current)
 
 Test "t#" reference
 -------------------
 
 
-  $ hg up t2
-  abort: cannot resolve "t2": no active topic
+  $ hg up s2
+  abort: cannot resolve "s2": branch "default" has only 0 non-public changesets
   [255]
   $ hg topic foo
   marked working directory as topic: foo
   $ hg up t42
   abort: cannot resolve "t42": topic "foo" has only 4 changesets
   [255]
-  $ hg up t2
+  $ hg up s42
+  abort: cannot resolve "s42": topic "foo" has only 4 changesets
+  [255]
+  $ hg up s2
   0 files updated, 0 files merged, 2 files removed, 0 files unresolved
   $ hg summary
   parent: 3:e629654d7050 
@@ -282,30 +285,30 @@
   $ hg topic --list
   ### topic: foo
   ### target: default (branch)
-  t4$ c_f (unstable)
-  t3$ c_e (unstable)
-  t2@ c_d (current)
-  t1: c_c
-  t0^ c_b (base)
-  $ hg up t3
+  s4$ c_f (unstable)
+  s3$ c_e (unstable)
+  s2@ c_d (current)
+  s1: c_c
+  s0^ c_b (base)
+  $ hg up s3
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg topic --list
   ### topic: foo
   ### target: default (branch)
-  t4$ c_f (unstable)
-  t3$ c_e (current unstable)
-  t2: c_d
-  t1: c_c
-  t0^ c_b (base)
+  s4$ c_f (unstable)
+  s3$ c_e (current unstable)
+  s2: c_d
+  s1: c_c
+  s0^ c_b (base)
   $ hg topic --list --color=debug
   [topic.stack.summary.topic|### topic: [topic.active|foo]]
   [topic.stack.summary.branches|### target: default (branch)]
-  [topic.stack.index topic.stack.index.unstable|t4][topic.stack.state topic.stack.state.unstable|$] [topic.stack.desc topic.stack.desc.unstable|c_f][topic.stack.state topic.stack.state.unstable| (unstable)]
-  [topic.stack.index topic.stack.index.current topic.stack.index.unstable|t3][topic.stack.state topic.stack.state.current topic.stack.state.unstable|$] [topic.stack.desc topic.stack.desc.current topic.stack.desc.unstable|c_e][topic.stack.state topic.stack.state.current topic.stack.state.unstable| (current unstable)]
-  [topic.stack.index topic.stack.index.clean|t2][topic.stack.state topic.stack.state.clean|:] [topic.stack.desc topic.stack.desc.clean|c_d]
-  [topic.stack.index topic.stack.index.clean|t1][topic.stack.state topic.stack.state.clean|:] [topic.stack.desc topic.stack.desc.clean|c_c]
-  [topic.stack.index topic.stack.index.base|t0][topic.stack.state topic.stack.state.base|^] [topic.stack.desc topic.stack.desc.base|c_b][topic.stack.state topic.stack.state.base| (base)]
-  $ hg up t2
+  [topic.stack.index topic.stack.index.unstable|s4][topic.stack.state topic.stack.state.unstable|$] [topic.stack.desc topic.stack.desc.unstable|c_f][topic.stack.state topic.stack.state.unstable| (unstable)]
+  [topic.stack.index topic.stack.index.current topic.stack.index.unstable|s3][topic.stack.state topic.stack.state.current topic.stack.state.unstable|$] [topic.stack.desc topic.stack.desc.current topic.stack.desc.unstable|c_e][topic.stack.state topic.stack.state.current topic.stack.state.unstable| (current unstable)]
+  [topic.stack.index topic.stack.index.clean|s2][topic.stack.state topic.stack.state.clean|:] [topic.stack.desc topic.stack.desc.clean|c_d]
+  [topic.stack.index topic.stack.index.clean|s1][topic.stack.state topic.stack.state.clean|:] [topic.stack.desc topic.stack.desc.clean|c_c]
+  [topic.stack.index topic.stack.index.base|s0][topic.stack.state topic.stack.state.base|^] [topic.stack.desc topic.stack.desc.base|c_b][topic.stack.state topic.stack.state.base| (base)]
+  $ hg up s2
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
 
 Also test the revset:
@@ -380,14 +383,14 @@
   $ hg top -l
   ### topic: foo (2 heads)
   ### target: default (branch)
-  t6@ c_h (current)
-  t5: c_g
-  t2^ c_d (base)
-  t4: c_f
-  t3: c_e
-  t2: c_d
-  t1: c_c
-  t0^ c_b (base)
+  s6@ c_h (current)
+  s5: c_g
+  s2^ c_d (base)
+  s4: c_f
+  s3: c_e
+  s2: c_d
+  s1: c_c
+  s0^ c_b (base)
 
 Case with multiple heads on the topic with unstability involved
 ---------------------------------------------------------------
@@ -424,14 +427,14 @@
   $ hg topic --list
   ### topic: foo (2 heads)
   ### target: default (branch)
-  t6: c_h
-  t5: c_g
-  t2^ c_D (base current)
-  t4$ c_f (unstable)
-  t3$ c_e (unstable)
-  t2@ c_D (current)
-  t1: c_c
-  t0^ c_b (base)
+  s6: c_h
+  s5: c_g
+  s2^ c_D (base current)
+  s4$ c_f (unstable)
+  s3$ c_e (unstable)
+  s2@ c_D (current)
+  s1: c_c
+  s0^ c_b (base)
 
 Trying to list non existing topic
   $ hg stack thisdoesnotexist
@@ -548,21 +551,21 @@
   $ hg stack
   ### topic: foobar
   ### target: default (branch), 3 behind
-  t2@ c_e (current)
+  s2@ c_e (current)
     ^ c_h
-  t1: c_D
-  t0^ c_c (base)
+  s1: c_D
+  s0^ c_c (base)
 
   $ hg stack foo
   ### topic: foo
   ### target: default (branch), ambiguous rebase destination - topic 'foo' has 3 heads
-  t4: c_f
+  s4: c_f
     ^ c_e
-  t3: c_h
-  t2: c_g
+  s3: c_h
+  s2: c_g
     ^ c_D
-  t1: c_c
-  t0^ c_b (base)
+  s1: c_c
+  s0^ c_b (base)
 
 case involving a merge
 ----------------------
@@ -638,24 +641,24 @@
   $ hg stack red
   ### topic: red
   ### target: default (branch), 6 behind
-  t5: c_H
+  s5: c_H
     ^ c_G
     ^ c_D
-  t4: c_C
-  t1^ c_B (base)
-  t3: c_F
-  t2: c_E
-  t1: c_B
-  t0^ c_A (base)
+  s4: c_C
+  s1^ c_B (base)
+  s3: c_F
+  s2: c_E
+  s1: c_B
+  s0^ c_A (base)
   $ hg stack blue
   ### topic: blue
   ### target: default (branch), ambiguous rebase destination - topic 'blue' has 3 heads
-  t3@ c_I (current)
+  s3@ c_I (current)
     ^ c_H
-  t2: c_D
+  s2: c_D
     ^ c_C
-  t1: c_G
-  t0^ c_F (base)
+  s1: c_G
+  s0^ c_F (base)
 
 Even with some obsolete and orphan changesets
 
@@ -703,24 +706,24 @@
   $ hg stack red
   ### topic: red
   ### target: default (branch), ambiguous rebase destination - topic 'red' has 3 heads
-  t5$ c_H (unstable)
+  s5$ c_H (unstable)
     ^ c_G
     ^ c_D
-  t4$ c_C (unstable)
-  t1^ c_B (base)
-  t3$ c_F (unstable)
-  t2$ c_E (unstable)
-  t1: c_B
-  t0^ c_A (base)
+  s4$ c_C (unstable)
+  s1^ c_B (base)
+  s3$ c_F (unstable)
+  s2$ c_E (unstable)
+  s1: c_B
+  s0^ c_A (base)
   $ hg stack blue
   ### topic: blue
   ### target: default (branch), ambiguous rebase destination - topic 'blue' has 3 heads
-  t3$ c_I (unstable)
+  s3$ c_I (unstable)
     ^ c_H
-  t2$ c_G (unstable)
+  s2$ c_G (unstable)
     ^ c_F
-  t1$ c_D (current unstable)
-  t0^ c_C (base unstable)
+  s1$ c_D (current unstable)
+  s0^ c_C (base unstable)
 
 more obsolescence
 
@@ -777,49 +780,49 @@
   $ hg stack red
   ### topic: red
   ### target: default (branch), ambiguous rebase destination - topic 'red' has 3 heads
-  t5$ c_H (unstable)
+  s5$ c_H (unstable)
     ^ c_G
     ^ c_D
-  t4$ c_F (unstable)
-  t3$ c_E (unstable)
-  t1^ c_B (base)
-  t2$ c_C (unstable)
-  t1: c_B
-  t0^ c_A (base)
+  s4$ c_F (unstable)
+  s3$ c_E (unstable)
+  s1^ c_B (base)
+  s2$ c_C (unstable)
+  s1: c_B
+  s0^ c_A (base)
   $ hg stack blue
   ### topic: blue
   ### target: default (branch), ambiguous rebase destination - topic 'blue' has 3 heads
-  t3$ c_I (unstable)
+  s3$ c_I (unstable)
     ^ c_H
-  t2$ c_G (unstable)
+  s2$ c_G (unstable)
     ^ c_F
-  t1$ c_D (current unstable)
-  t0^ c_C (base unstable)
+  s1$ c_D (current unstable)
+  s0^ c_C (base unstable)
 
 Test stack behavior with a split
 --------------------------------
 
 get things linear again
 
-  $ hg rebase -r t1 -d default
+  $ hg rebase -r s1 -d default
   rebasing 16:1d84ec948370 "c_D" (tip blue)
   switching to topic blue
-  $ hg rebase -r t2 -d t1
+  $ hg rebase -r s2 -d s1
   rebasing 13:3ab2eedae500 "c_G" (blue)
-  $ hg rebase -r t3 -d t2
+  $ hg rebase -r s3 -d s2
   rebasing 8:3bfe800e0486 "c_I" (blue)
   $ hg stack
   ### topic: blue
   ### target: default (branch)
-  t3: c_I
-  t2: c_G
-  t1@ c_D (current)
-  t0^ c_A (base)
+  s3: c_I
+  s2: c_G
+  s1@ c_D (current)
+  s0^ c_A (base)
 
 making a split
 (first get something to split)
 
-  $ hg up t2
+  $ hg up s2
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg status --change .
   A ggg
@@ -832,10 +835,10 @@
   $ hg stack
   ### topic: blue
   ### target: default (branch)
-  t3$ c_I (unstable)
-  t2@ c_G (current)
-  t1: c_D
-  t0^ c_A (base)
+  s3$ c_I (unstable)
+  s2@ c_G (current)
+  s1: c_D
+  s0^ c_A (base)
   $ hg --config extensions.evolve=  --config ui.interactive=yes split << EOF
   > y
   > y
@@ -912,8 +915,8 @@
   $ hg stack
   ### topic: blue
   ### target: default (branch)
-  t4$ c_I (unstable)
-  t3@ c_G (current)
-  t2: c_G
-  t1: c_D
-  t0^ c_A (base)
+  s4$ c_I (unstable)
+  s3@ c_G (current)
+  s2: c_G
+  s1: c_D
+  s0^ c_A (base)