diff -r 1df2f0e1dfd2 -r c7b45db8f317 mercurial/templatekw.py
--- a/mercurial/templatekw.py	Sat Dec 02 16:08:24 2017 +0900
+++ b/mercurial/templatekw.py	Sat Dec 02 16:29:49 2017 +0900
@@ -17,6 +17,7 @@
     encoding,
     error,
     hbisect,
+    i18n,
     obsutil,
     patch,
     pycompat,
@@ -301,6 +302,30 @@
 
     return getrenamed
 
+def getlogcolumns():
+    """Return a dict of log column labels"""
+    _ = pycompat.identity  # temporarily disable gettext
+    # i18n: column positioning for "hg log"
+    columns = _('bookmark:    %s\n'
+                'branch:      %s\n'
+                'changeset:   %s\n'
+                'copies:      %s\n'
+                'date:        %s\n'
+                'extra:       %s=%s\n'
+                'files+:      %s\n'
+                'files-:      %s\n'
+                'files:       %s\n'
+                'instability: %s\n'
+                'manifest:    %s\n'
+                'obsolete:    %s\n'
+                'parent:      %s\n'
+                'phase:       %s\n'
+                'summary:     %s\n'
+                'tag:         %s\n'
+                'user:        %s\n')
+    return dict(zip([s.split(':', 1)[0] for s in columns.splitlines()],
+                    i18n._(columns).splitlines(True)))
+
 # default templates internally used for rendering of lists
 defaulttempl = {
     'parent': '{rev}:{node|formatnode} ',