[PATCH V2] absorb: clarify the reason for not finding changesets to modify

[Matt Harbison]

# HG changeset patch
# User Matt Harbison <matt_harbison at yahoo.com>
# Date 1536108502 14400
#      Tue Sep 04 20:48:22 2018 -0400
# Node ID 53ed650843c5c1e1b7a829be525ca8087c68906f
# Parent  481db51c83e9bb5642be1ea1e88771dae5590552
absorb: clarify the reason for not finding changesets to modify

I'm used to pushing to non-publishing repos, so this was the last thing I
thought to check.

diff --git a/hgext/absorb.py b/hgext/absorb.py
--- a/hgext/absorb.py
+++ b/hgext/absorb.py
@@ -917,7 +917,7 @@ def absorb(ui, repo, stack=None, targetc
                       'be analysed\n')
                     % limit)
     if not stack:
-        raise error.Abort(_('no changeset to change'))
+        raise error.Abort(_('no mutable changeset to change'))
     if targetctx is None: # default to working copy
         targetctx = repo[None]
     if pats is None:
diff --git a/tests/test-absorb.t b/tests/test-absorb.t
--- a/tests/test-absorb.t
+++ b/tests/test-absorb.t
@@ -18,7 +18,7 @@
 Do not crash with empty repo:
 
   $ hg absorb
-  abort: no changeset to change
+  abort: no mutable changeset to change
   [255]
 
 Make some commits:
@@ -225,7 +225,7 @@ Merge commit will not be changed:
   $ echo 2 >> m1
   $ echo 2 >> m2
   $ hg absorb
-  abort: no changeset to change
+  abort: no mutable changeset to change
   [255]
   $ hg revert -q -C m1 m2