[PATCH 2 of 2] show: add basic labels to work template

[Gregory Szorc]

# HG changeset patch
# User Gregory Szorc <gregory.szorc at gmail.com>
# Date 1492539008 25200
#      Tue Apr 18 11:10:08 2017 -0700
# Node ID 7f5f78179f5f6afc0f4bea52aa03f1431e03d3d9
# Parent  d8d4b4acc68859f90f8759309803b116b67a9371
show: add basic labels to work template

`hg show work` is much more usable if output is colored. This patch
implements coloring via label() in a very hacky way.

In a default Mercurial install, you'll see yellow node labels for all
phases. Branches and bookmarks use the same formatting as the commit
message. So this change doesn't help much in a default install. But if
you have a custom colors defined for these things, output is much more
readable.

The implementation obviously needs some work. But for a minor change
on a feature that isn't convered by BC, this seems like a clear win
for the feature in 4.2.

diff --git a/mercurial/templates/map-cmdline.show b/mercurial/templates/map-cmdline.show
--- a/mercurial/templates/map-cmdline.show
+++ b/mercurial/templates/map-cmdline.show
@@ -1,3 +1,9 @@
-# TODO add label() once we figure out which namespace the labels belong on.
+# TODO there are a few deficiencies in this file:
+# * Due to the way the file is loaded, references to other entities in the
+#   template doesn't work. That requires us to inline.
+# * The "namespace" of the labels needs to be worked out. We currently
+#   piggyback on existing values so color works.
+# * Obsolescence isn't considered for node labels. See _cset_labels in
+#   map-cmdline.default.
 showbookmarks = '{if(active, "*", " ")} {pad(bookmark, longestbookmarklen + 4)}{shortest(node, 5)}\n'
-showwork = '{shortest(node, 5)}{if(branches, " ({branch})")}{if(bookmarks, " ({bookmarks})")} {desc|firstline}'
+showwork = '{label("log.changeset changeset.{phase}", shortest(node, 5))}{if(branches, " ({label("log.branch", branch)})")}{if(bookmarks, " ({label("log.bookmarks", bookmarks)})")} {label("log.description", desc|firstline)}'