templatekw: port implementation of showparents() from changeset_templater

It isn't cool, but we can peek at ui flag via repo.ui. So, it is possible
to implement showparents() in templatekw, and therefore we can eliminate the
dockeywords hack.

mercurial/cmdutil.py

@@ -1428,24 +1428,8 b' class changeset_templater(changeset_prin'
 
     def _show(self, ctx, copies, matchfn, props):
         '''show a single changeset or file revision'''
-
-        showlist = templatekw.showlist
-
-        # showparents() behavior depends on ui trace level which
-        # causes unexpected behaviors at templating level and makes
-        # it harder to extract it in a standalone function. Its
-        # behavior cannot be changed so leave it here for now.
-        def showparents(**args):
-            ctx = args['ctx']
-            parents = [[('rev', p.rev()),
-                        ('node', p.hex()),
-                        ('phase', p.phasestr())]
-                       for p in scmutil.meaningfulparents(self.repo, ctx)]
-            return showlist('parent', parents, **args)
-
         props = props.copy()
         props.update(templatekw.keywords)
-        props['parents'] = showparents
         props['templ'] = self.t
         props['ctx'] = ctx
         props['repo'] = self.repo

mercurial/templatekw.py

@@ -397,11 +397,17 b' def showp2node(repo, ctx, templ, **args)'
     parent, all digits are 0."""
     return ctx.p2().hex()
 
-def _showparents(**args):
+def showparents(**args):
     """:parents: List of strings. The parents of the changeset in "rev:node"
     format. If the changeset has only one "natural" parent (the predecessor
     revision) nothing is shown."""
-    pass
+    repo = args['repo']
+    ctx = args['ctx']
+    parents = [[('rev', p.rev()),
+                ('node', p.hex()),
+                ('phase', p.phasestr())]
+               for p in scmutil.meaningfulparents(repo, ctx)]
+    return showlist('parent', parents, **args)
 
 def showphase(repo, ctx, templ, **args):
     """:phase: String. The changeset phase name."""
@@ -491,6 +497,7 b' keywords = {'
     'p1node': showp1node,
     'p2rev': showp2rev,
     'p2node': showp2node,
+    'parents': showparents,
     'phase': showphase,
     'phaseidx': showphaseidx,
     'rev': showrev,
@@ -499,7 +506,6 b' keywords = {'
 }
 
 dockeywords = {
-    'parents': _showparents,
 }
 dockeywords.update(keywords)
 del dockeywords['branches']