[PATCH 1 of 6] rebase: improve error message for more than one external parent

[Mads Kiilerich]

# HG changeset patch
# User Mads Kiilerich <madski at unity3d.com>
# Date 1382542933 -28800
#      Wed Oct 23 23:42:13 2013 +0800
# Branch stable
# Node ID 9c9093febeb627dca63bc30c7ecf515feaea5c24
# Parent  b7f76db06dc0f1c85f05256eaba7ac7559e811e9
rebase: improve error message for more than one external parent

diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -403,7 +403,7 @@ def checkexternal(repo, state, targetanc
                         and p.rev() not in targetancestors):
                 if external != nullrev:
                     raise util.Abort(_('unable to collapse, there is more '
-                            'than one external parent'))
+                            'than one external parent to %s') % external)
                 external = p.rev()
     return external
 
diff --git a/tests/test-rebase-collapse.t b/tests/test-rebase-collapse.t
--- a/tests/test-rebase-collapse.t
+++ b/tests/test-rebase-collapse.t
@@ -226,7 +226,7 @@ Rebase and collapse - more than one exte
   $ cd b1
 
   $ hg rebase -s 2 --collapse
-  abort: unable to collapse, there is more than one external parent
+  abort: unable to collapse, there is more than one external parent to 1
   [255]
 
 Rebase and collapse - E onto H: