--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-issue1877.t	Mon Mar 14 23:50:28 2011 +0100
@@ -0,0 +1,45 @@
+http://mercurial.selenic.com/bts/issue1877
+
+  $ hg init a
+  $ cd a
+  $ echo a > a
+  $ hg add a
+  $ hg ci -m 'a'
+  $ echo b > a
+  $ hg ci -m'b'
+  $ hg up 0
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg book main
+  $ hg book
+   * main                      0:cb9a9f314b8b
+  $ echo c > c
+  $ hg add c
+  $ hg ci -m'c'
+  created new head
+  $ hg book
+   * main                      2:d36c0562f908
+  $ hg heads
+  changeset:   2:d36c0562f908
+  bookmark:    main
+  tag:         tip
+  parent:      0:cb9a9f314b8b
+  user:        test
+  date:        Thu Jan 01 00:00:00 1970 +0000
+  summary:     c
+  
+  changeset:   1:1e6c11564562
+  user:        test
+  date:        Thu Jan 01 00:00:00 1970 +0000
+  summary:     b
+  
+  $ hg up 1e6c11564562
+  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ hg merge main
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  (branch merge, don't forget to commit)
+  $ hg book
+     main                      2:d36c0562f908
+  $ hg ci -m'merge'
+  $ hg book
+     main                      2:d36c0562f908
+