merge: make 'nothing to merge' aborts consistent

Makes the 'nothing to merge' abort messages in commands.py consistent with
those in merge.py. Also makes commands.merge() and merge.update() use hints.
The tests show the changes.

mercurial/commands.py

@@ -4042,10 +4042,10 b' def merge(ui, repo, node=None, **opts):'
                                    "please merge with an explicit rev")
                                  % branch,
                                  hint=_("run 'hg heads' to see all heads"))
-            msg = _('there is nothing to merge')
+            msg, hint = _('nothing to merge'), None
             if parent != repo.lookup(branch):
-                msg = _('%s - use "hg update" instead') % msg
-            raise util.Abort(msg)
+                hint = _("use 'hg update' instead")
+            raise util.Abort(msg, hint=hint)
 
         if parent not in bheads:
             raise util.Abort(_('working directory not at a head revision'),

mercurial/merge.py

@@ -519,11 +519,12 b' def update(repo, node, branchmerge, forc'
                                    " has no effect"))
             elif pa == p1:
                 if p1.branch() == p2.branch():
-                    raise util.Abort(_("nothing to merge (use 'hg update'"
-                                       " or check 'hg heads')"))
+                    raise util.Abort(_("nothing to merge"),
+                                     hint=_("use 'hg update' "
+                                            "or check 'hg heads'"))
             if not force and (wc.files() or wc.deleted()):
-                raise util.Abort(_("outstanding uncommitted changes "
-                                   "(use 'hg status' to list changes)"))
+                raise util.Abort(_("outstanding uncommitted changes"),
+                                 hint=_("use 'hg status' to list changes"))
             for s in wc.substate:
                 if wc.sub(s).dirty():
                     raise util.Abort(_("outstanding uncommitted changes in "

tests/test-merge-default.t

@@ -66,7 +66,7 b' Should succeed - 2 heads:'
 Should fail because at tip:
 
   $ hg merge
-  abort: there is nothing to merge
+  abort: nothing to merge
   [255]
 
   $ hg up 0
@@ -75,7 +75,8 b' Should fail because at tip:'
 Should fail because there is only one head:
 
   $ hg merge
-  abort: there is nothing to merge - use "hg update" instead
+  abort: nothing to merge
+  (use 'hg update' instead)
   [255]
 
   $ hg up 3

tests/test-merge-force.t

@@ -19,7 +19,8 b' Local deleted a file, remote removed'
 Should fail, since there are deleted files:
 
   $ hg merge
-  abort: outstanding uncommitted changes (use 'hg status' to list changes)
+  abort: outstanding uncommitted changes
+  (use 'hg status' to list changes)
   [255]
 
 Should succeed with --force:

tests/test-merge1.t

@@ -108,7 +108,8 b' Contents of b should be "this is file b1'
   $ echo This is file b22 > b
 merge fails
   $ hg merge 2
-  abort: outstanding uncommitted changes (use 'hg status' to list changes)
+  abort: outstanding uncommitted changes
+  (use 'hg status' to list changes)
   [255]
 merge expected!
   $ hg merge -f 2
@@ -144,7 +145,8 b' merge expected!'
   $ echo This is file b33 > b
 merge of b should fail
   $ hg merge 2
-  abort: outstanding uncommitted changes (use 'hg status' to list changes)
+  abort: outstanding uncommitted changes
+  (use 'hg status' to list changes)
   [255]
 merge of b expected
   $ hg merge -f 2

tests/test-up-local-change.t

@@ -84,7 +84,8 b''
   summary:     1
   
   $ hg --debug merge
-  abort: there is nothing to merge - use "hg update" instead
+  abort: nothing to merge
+  (use 'hg update' instead)
   [255]
   $ hg parents
   changeset:   0:c19d34741b0a
@@ -169,7 +170,8 b' create a second head'
   abort: crosses branches (merge branches or use --clean to discard changes)
   [255]
   $ hg --debug merge
-  abort: outstanding uncommitted changes (use 'hg status' to list changes)
+  abort: outstanding uncommitted changes
+  (use 'hg status' to list changes)
   [255]
   $ hg --debug merge -f
     searching for copies back to rev 1