--- a/mercurial/commands.py	Thu Aug 18 14:23:29 2016 +0900
+++ b/mercurial/commands.py	Thu Aug 18 14:52:06 2016 +0900
@@ -4397,20 +4397,23 @@
         else:
             iter = [('', l) for l in states]
         for change, l in iter:
-            cols = [(fn, 'filename'), (str(rev), 'rev')]
-
-            if opts.get('line_number'):
-                cols.append((str(l.linenum), 'linenumber'))
+            cols = [
+                ('filename', fn, True),
+                ('rev', str(rev), True),
+                ('linenumber', str(l.linenum), opts.get('line_number')),
+            ]
             if opts.get('all'):
-                cols.append((change, 'change'))
-            if opts.get('user'):
-                cols.append((ui.shortuser(ctx.user()), 'user'))
-            if opts.get('date'):
-                cols.append((datefunc(ctx.date()), 'date'))
-            for col, field in cols[:-1]:
-                ui.write(col, label='grep.%s' % field)
-                ui.write(sep, label='grep.sep')
-            ui.write(cols[-1][0], label='grep.%s' % cols[-1][1])
+                cols.append(('change', change, True))
+            cols.extend([
+                ('user', ui.shortuser(ctx.user()), opts.get('user')),
+                ('date', datefunc(ctx.date()), opts.get('date')),
+            ])
+            lastcol = next(name for name, data, cond in reversed(cols) if cond)
+            for name, data, cond in cols:
+                if cond:
+                    ui.write(data, label='grep.%s' % name)
+                if cond and name != lastcol:
+                    ui.write(sep, label='grep.sep')
             if not opts.get('files_with_matches'):
                 ui.write(sep, label='grep.sep')
                 if not opts.get('text') and binary():