tests: unify tests-debugindexdot

tests/test-debugindexdot.t

@@ -1,17 +1,23 b''
-#!/bin/sh
+Just exercize debugindexdot
+Create a short file history including a merge.
+  $ hg init t
+  $ cd t
+  $ echo a > a
+  $ hg ci -qAm t1 -d '0 0'
+  $ echo a >> a
+  $ hg ci -m t2 -d '1 0'
+  $ hg up -qC 0
+  $ echo b >> a
+  $ hg ci -m t3 -d '2 0'
+  created new head
+  $ HGMERGE=true hg merge -q
+  $ hg ci -m merge -d '3 0'
 
-# Just exercize debugindexdot
-# Create a short file history including a merge.
-hg init t
-cd t
-echo a > a
-hg ci -qAm t1 -d '0 0'
-echo a >> a
-hg ci -m t2 -d '1 0'
-hg up -qC 0
-echo b >> a
-hg ci -m t3 -d '2 0'
-HGMERGE=true hg merge -q
-hg ci -m merge -d '3 0'
-
-hg debugindexdot .hg/store/data/a.i
+  $ hg debugindexdot .hg/store/data/a.i
+  digraph G {
+  	-1 -> 0
+  	0 -> 1
+  	0 -> 2
+  	2 -> 3
+  	1 -> 3
+  }