graft: make skip messages more helpful

This makes it possible for the user to understand and accept or work around
what is happening.

mercurial/commands.py

@@ -3021,11 +3021,12 b' def graft(ui, repo, *revs, **opts):'
         if n in ids:
             r = repo[n].rev()
             if r in revs:
-                ui.warn(_('skipping already grafted revision %s\n') % r)
+                ui.warn(_('skipping revision %s (already grafted to %s)\n')
+                        % (r, rev))
                 revs.remove(r)
             elif ids[n] in revs:
                 ui.warn(_('skipping already grafted revision %s '
-                            '(same origin %d)\n') % (ids[n], r))
+                            '(%s also has origin %d)\n') % (ids[n], rev, r))
                 revs.remove(ids[n])
         elif ctx.hex() in ids:
             r = ids[ctx.hex()]

tests/test-graft.t

@@ -117,7 +117,7 b' Graft out of order, skipping a merge and'
 
   $ hg graft 1 5 4 3 'merge()' 2 -n
   skipping ungraftable merge revision 6
-  skipping already grafted revision 2
+  skipping revision 2 (already grafted to 7)
   grafting revision 1
   grafting revision 5
   grafting revision 4
@@ -126,7 +126,7 b' Graft out of order, skipping a merge and'
   $ hg graft 1 5 4 3 'merge()' 2 --debug
   skipping ungraftable merge revision 6
   scanning for duplicate grafts
-  skipping already grafted revision 2
+  skipping revision 2 (already grafted to 7)
   grafting revision 1
     searching for copies back to rev 1
     unmatched files in local:
@@ -196,9 +196,9 b' Graft again:'
 
   $ hg graft 1 5 4 3 'merge()' 2
   skipping ungraftable merge revision 6
-  skipping already grafted revision 2
-  skipping already grafted revision 1
-  skipping already grafted revision 5
+  skipping revision 2 (already grafted to 7)
+  skipping revision 1 (already grafted to 8)
+  skipping revision 5 (already grafted to 9)
   grafting revision 4
   merging e
   warning: conflicts during merge.
@@ -314,18 +314,18 b' Disallow grafting an already grafted cse'
 Disallow grafting already grafted csets with the same origin onto each other
   $ hg up -q 13
   $ hg graft 2
-  skipping already grafted revision 2
+  skipping revision 2 (already grafted to 13)
   [255]
   $ hg graft 7
-  skipping already grafted revision 7 (same origin 2)
+  skipping already grafted revision 7 (13 also has origin 2)
   [255]
 
   $ hg up -q 7
   $ hg graft 2
-  skipping already grafted revision 2
+  skipping revision 2 (already grafted to 7)
   [255]
   $ hg graft tip
-  skipping already grafted revision 13 (same origin 2)
+  skipping already grafted revision 13 (7 also has origin 2)
   [255]
 
 Graft with --log