templatekw: introduce active subkeyword from bookmarks keyword

Today, the terms 'active' and 'current' are interchangeably used throughout the
codebase in reference to the active bookmark (the bookmark that will be updated
with the next commit). This leads to confusion among developers and users.
This patch is part of a series to standardize the usage to 'active' throughout
the mercurial codebase and user interface.

mercurial/help/templates.txt

@@ -90,9 +90,9 @@ Some sample command line templates:
 
    $ hg log -r 0 --template "{join(extras, '\n')}\n"
 
-- Mark the current bookmark with '*'::
+- Mark the active bookmark with '*'::
 
-   $ hg log --template "{bookmarks % '{bookmark}{ifeq(bookmark, current, \"*\")} '}\n"
+   $ hg log --template "{bookmarks % '{bookmark}{ifeq(bookmark, active, \"*\")} '}\n"
 
 - Mark the working copy parent with '@'::
 

mercurial/templatekw.py

@@ -206,12 +206,12 @@ def showbranches(**args):
 
 def showbookmarks(**args):
     """:bookmarks: List of strings. Any bookmarks associated with the
-    changeset.
+    changeset. Also sets 'active', the name of the active bookmark.
     """
     repo = args['ctx']._repo
     bookmarks = args['ctx'].bookmarks()
-    current = repo._activebookmark
-    makemap = lambda v: {'bookmark': v, 'current': current}
+    active = repo._activebookmark
+    makemap = lambda v: {'bookmark': v, 'active': active, 'current': active}
     f = _showlist('bookmark', bookmarks, **args)
     return _hybrid(f, bookmarks, makemap, lambda x: x['bookmark'])
 

tests/test-command-template.t

@@ -3086,7 +3086,7 @@ Test current bookmark templating
 
   $ hg book foo
   $ hg book bar
-  $ hg log --template "{rev} {bookmarks % '{bookmark}{ifeq(bookmark, current, \"*\")} '}\n"
+  $ hg log --template "{rev} {bookmarks % '{bookmark}{ifeq(bookmark, active, \"*\")} '}\n"
   2 bar* foo 
   1 
   0