test-obsolete: change a marker so it is relevant to the exchanged set

We are going to only exchange markers relevant to the exchanged
changesets. So we need to change this marker to use a known changeset as
a successor instead of a precursor.

tests/test-obsolete.t

@@ -367,7 +367,7 b' On pull'
 
   $ hg init tmpe
   $ cd tmpe
-  $ hg debugobsolete -d '1339 0' 2448244824482448244824482448244824482448 1339133913391339133913391339133913391339
+  $ hg debugobsolete -d '1339 0' 1339133913391339133913391339133913391339 ca819180edb99ed25ceafb3e9584ac287e240b00
   $ hg pull ../tmpb
   pulling from ../tmpb
   requesting all changes
@@ -377,7 +377,7 b' On pull'
   added 4 changesets with 4 changes to 4 files (+1 heads)
   (run 'hg heads' to see heads, 'hg merge' to merge)
   $ hg debugobsolete
-  2448244824482448244824482448244824482448 1339133913391339133913391339133913391339 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
+  1339133913391339133913391339133913391339 ca819180edb99ed25ceafb3e9584ac287e240b00 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
   245bde4270cd1072a27757984f9cda8ba26f08ca cdbce2fbb16313928851e97e0d85413f3f7eb77f C (Thu Jan 01 00:00:44 1970 -0000) {'user': 'test'}
   cdbce2fbb16313928851e97e0d85413f3f7eb77f ca819180edb99ed25ceafb3e9584ac287e240b00 0 (Thu Jan 01 00:22:17 1970 +0000) {'user': 'test'}
   ca819180edb99ed25ceafb3e9584ac287e240b00 1337133713371337133713371337133713371337 0 (Thu Jan 01 00:22:18 1970 +0000) {'user': 'test'}
@@ -398,7 +398,7 b' On push'
   ca819180edb99ed25ceafb3e9584ac287e240b00 1337133713371337133713371337133713371337 0 (Thu Jan 01 00:22:18 1970 +0000) {'user': 'test'}
   1337133713371337133713371337133713371337 5601fb93a350734d935195fee37f4054c529ff39 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
   5601fb93a350734d935195fee37f4054c529ff39 6f96419950729f3671185b847352890f074f7557 1 (Thu Jan 01 00:22:18 1970 +0000) {'user': 'test'}
-  2448244824482448244824482448244824482448 1339133913391339133913391339133913391339 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
+  1339133913391339133913391339133913391339 ca819180edb99ed25ceafb3e9584ac287e240b00 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
 
 detect outgoing obsolete and unstable
 ---------------------------------------
@@ -540,7 +540,7 b' Reminder of the repo situation'
 List of all markers
 
   $ hg debugobsolete
-  2448244824482448244824482448244824482448 1339133913391339133913391339133913391339 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
+  1339133913391339133913391339133913391339 ca819180edb99ed25ceafb3e9584ac287e240b00 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
   245bde4270cd1072a27757984f9cda8ba26f08ca cdbce2fbb16313928851e97e0d85413f3f7eb77f C (Thu Jan 01 00:00:44 1970 -0000) {'user': 'test'}
   cdbce2fbb16313928851e97e0d85413f3f7eb77f ca819180edb99ed25ceafb3e9584ac287e240b00 0 (Thu Jan 01 00:22:17 1970 +0000) {'user': 'test'}
   ca819180edb99ed25ceafb3e9584ac287e240b00 1337133713371337133713371337133713371337 0 (Thu Jan 01 00:22:18 1970 +0000) {'user': 'test'}
@@ -562,6 +562,7 b' List of changesets with a longer chain, '
 
   $ hg debugobsolete --hidden --rev 3
   1337133713371337133713371337133713371337 5601fb93a350734d935195fee37f4054c529ff39 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
+  1339133913391339133913391339133913391339 ca819180edb99ed25ceafb3e9584ac287e240b00 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
   245bde4270cd1072a27757984f9cda8ba26f08ca cdbce2fbb16313928851e97e0d85413f3f7eb77f C (Thu Jan 01 00:00:44 1970 -0000) {'user': 'test'}
   5601fb93a350734d935195fee37f4054c529ff39 6f96419950729f3671185b847352890f074f7557 1 (Thu Jan 01 00:22:18 1970 +0000) {'user': 'test'}
   94b33453f93bdb8d457ef9b770851a618bf413e1 0 {6f96419950729f3671185b847352890f074f7557} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
@@ -572,6 +573,7 b' List of both'
 
   $ hg debugobsolete --hidden --rev 3::6
   1337133713371337133713371337133713371337 5601fb93a350734d935195fee37f4054c529ff39 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
+  1339133913391339133913391339133913391339 ca819180edb99ed25ceafb3e9584ac287e240b00 0 (Thu Jan 01 00:22:19 1970 +0000) {'user': 'test'}
   245bde4270cd1072a27757984f9cda8ba26f08ca cdbce2fbb16313928851e97e0d85413f3f7eb77f C (Thu Jan 01 00:00:44 1970 -0000) {'user': 'test'}
   5601fb93a350734d935195fee37f4054c529ff39 6f96419950729f3671185b847352890f074f7557 1 (Thu Jan 01 00:22:18 1970 +0000) {'user': 'test'}
   94b33453f93bdb8d457ef9b770851a618bf413e1 0 {6f96419950729f3671185b847352890f074f7557} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}