--- a/mercurial/hbisect.py	Mon Dec 31 18:20:34 2007 -0600
+++ b/mercurial/hbisect.py	Mon Dec 31 18:20:34 2007 -0600
@@ -30,7 +30,7 @@
                     ancestors[prev] = None
 
         if ancestors[badrev] is None:
-            return None, None
+            return badrev, None
         return badrev, ancestors
 
     good = 0
@@ -38,10 +38,10 @@
     if not ancestors: # looking for bad to good transition?
         good = 1
         badrev, ancestors = buildancestors(state['good'], state['bad'])
+    bad = changelog.node(badrev)
     if not ancestors: # now we're confused
         raise util.Abort(_("Inconsistent state, %s:%s is good and bad")
                          % (badrev, hg.short(bad)))
-    bad = changelog.node(badrev)
 
     # build children dict
     children = {}

--- a/tests/test-bisect	Mon Dec 31 18:20:34 2007 -0600
+++ b/tests/test-bisect	Mon Dec 31 18:20:34 2007 -0600
@@ -27,6 +27,8 @@
 hg bisect -b
 hg bisect -g 1
 hg bisect -g
+echo skip
+hg bisect -s
 hg bisect -g
 hg bisect -g
 hg bisect -b
@@ -37,7 +39,18 @@
 hg bisect -b null
 hg bisect -g tip
 hg bisect -g
+echo skip
+hg bisect -s
 hg bisect -g
 hg bisect -g
 hg bisect -b
 hg bisect -g
+
+hg bisect -r
+hg bisect -g tip
+hg bisect -b tip || echo error
+
+hg bisect -r
+hg bisect -g null
+hg bisect -bU tip
+hg id
\ No newline at end of file

--- a/tests/test-bisect.out	Mon Dec 31 18:20:34 2007 -0600
+++ b/tests/test-bisect.out	Mon Dec 31 18:20:34 2007 -0600
@@ -202,7 +202,10 @@
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 Testing changeset 23:5ec79163bff4 (15 changesets remaining, ~3 tests)
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
-Testing changeset 27:288867a866e9 (8 changesets remaining, ~3 tests)
+skip
+Testing changeset 24:10e0acd3809e (15 changesets remaining, ~3 tests)
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+Testing changeset 27:288867a866e9 (7 changesets remaining, ~2 tests)
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 Testing changeset 29:b5bd63375ab9 (4 changesets remaining, ~2 tests)
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
@@ -219,15 +222,22 @@
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 Testing changeset 7:03750880c6b5 (16 changesets remaining, ~4 tests)
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
-Testing changeset 3:b53bea5e2fcb (8 changesets remaining, ~3 tests)
+skip
+Testing changeset 6:a3d5c6fdf0d3 (16 changesets remaining, ~4 tests)
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
-Testing changeset 1:5cd978ea5149 (4 changesets remaining, ~2 tests)
+Testing changeset 2:db07c04beaca (7 changesets remaining, ~2 tests)
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
-Testing changeset 2:db07c04beaca (2 changesets remaining, ~1 tests)
+Testing changeset 0:b99c7b9c8e11 (3 changesets remaining, ~1 tests)
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+Testing changeset 1:5cd978ea5149 (2 changesets remaining, ~1 tests)
 1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 The first good revision is:
-changeset:   2:db07c04beaca
+changeset:   1:5cd978ea5149
 user:        test
-date:        Thu Jan 01 00:00:02 1970 +0000
-summary:     msg 2
+date:        Thu Jan 01 00:00:01 1970 +0000
+summary:     msg 1
 
+abort: Inconsistent state, 31:58c80a7c8a40 is good and bad
+error
+Testing changeset 15:e7fa0811edb0 (32 changesets remaining, ~5 tests)
+5cd978ea5149