--- a/mercurial/commands.py	Mon Jun 04 00:50:19 2012 +0200
+++ b/mercurial/commands.py	Thu Jun 07 19:20:44 2012 +0200
@@ -17,7 +17,7 @@
 import minirst, revset, fileset
 import dagparser, context, simplemerge
 import random, setdiscovery, treediscovery, dagutil, pvec
-import phases
+import phases, obsolete
 
 table = {}
 
@@ -2050,19 +2050,29 @@
     ui.write("%s\n" % ("".join([f and "1" or "0" for f in flags])))
 
 @command('debugobsolete', [] + commitopts2,
-         _('OBSOLETED [REPLACEMENT] [REPL...'))
-def debugobsolete(ui, repo, precursor, *successors, **opts):
+         _('[OBSOLETED [REPLACEMENT] [REPL... ]'))
+def debugobsolete(ui, repo, precursor=None, *successors, **opts):
     """create arbitrary obsolete marker"""
-    metadata = {}
-    if 'date' in opts:
-        metadata['date'] = opts['date']
-    metadata['user'] = opts['user'] or ui.username()
-    succs = tuple(bin(succ) for succ in successors)
-    l = repo.lock()
-    try:
-        repo.obsstore.create(bin(precursor), succs, 0, metadata)
-    finally:
-        l.release()
+    if precursor is not None:
+        metadata = {}
+        if 'date' in opts:
+            metadata['date'] = opts['date']
+        metadata['user'] = opts['user'] or ui.username()
+        succs = tuple(bin(succ) for succ in successors)
+        l = repo.lock()
+        try:
+            repo.obsstore.create(bin(precursor), succs, 0, metadata)
+        finally:
+            l.release()
+    else:
+        for mctx in obsolete.allmarkers(repo):
+            ui.write(hex(mctx.precnode()))
+            for repl in mctx.succnodes():
+                ui.write(' ')
+                ui.write(hex(repl))
+            ui.write(' %X ' % mctx._data[2])
+            ui.write(mctx.metadata())
+            ui.write('\n')
 
 @command('debugpushkey', [], _('REPO NAMESPACE [KEY OLD NEW]'))
 def debugpushkey(ui, repopath, namespace, *keyinfo, **opts):

--- a/tests/test-obsolete.t	Mon Jun 04 00:50:19 2012 +0200
+++ b/tests/test-obsolete.t	Thu Jun 07 19:20:44 2012 +0200
@@ -16,6 +16,8 @@
 
   $ mkcommit kill_me
   $ hg debugobsolete -d '0 0' `getid kill_me` -u babar
+  $ hg debugobsolete
+  97b7c2d76b1845ed3eb988cd612611e72406cef0 0 {'date': '0 0', 'user': 'babar'}
   $ cd ..
 
 Killing a single changeset with replacement
@@ -30,6 +32,8 @@
   $ mkcommit new_c
   created new head
   $ hg debugobsolete `getid original_c`  `getid new_c` -d '56 12'
+  $ hg debugobsolete
+  245bde4270cd1072a27757984f9cda8ba26f08ca cdbce2fbb16313928851e97e0d85413f3f7eb77f 0 {'date': '56 12', 'user': 'test'}
 
 do it again (it read the obsstore before adding new changeset)
 
@@ -38,6 +42,9 @@
   $ mkcommit new_2_c
   created new head
   $ hg debugobsolete -d '1337 0' `getid new_c` `getid new_2_c`
+  $ hg debugobsolete
+  245bde4270cd1072a27757984f9cda8ba26f08ca cdbce2fbb16313928851e97e0d85413f3f7eb77f 0 {'date': '56 12', 'user': 'test'}
+  cdbce2fbb16313928851e97e0d85413f3f7eb77f ca819180edb99ed25ceafb3e9584ac287e240b00 0 {'date': '1337 0', 'user': 'test'}
 
 Register two markers with a missing node
 
@@ -47,3 +54,8 @@
   created new head
   $ hg debugobsolete -d '1338 0' `getid new_2_c` 1337133713371337133713371337133713371337
   $ hg debugobsolete -d '1339 0' 1337133713371337133713371337133713371337 `getid new_3_c`
+  $ hg debugobsolete
+  245bde4270cd1072a27757984f9cda8ba26f08ca cdbce2fbb16313928851e97e0d85413f3f7eb77f 0 {'date': '56 12', 'user': 'test'}
+  cdbce2fbb16313928851e97e0d85413f3f7eb77f ca819180edb99ed25ceafb3e9584ac287e240b00 0 {'date': '1337 0', 'user': 'test'}
+  ca819180edb99ed25ceafb3e9584ac287e240b00 1337133713371337133713371337133713371337 0 {'date': '1338 0', 'user': 'test'}
+  1337133713371337133713371337133713371337 5601fb93a350734d935195fee37f4054c529ff39 0 {'date': '1339 0', 'user': 'test'}