changeset 29863:0418cdf67efb

grep: build list of all columns regardless of display options

These columns should always be available in JSON or template outputs. The
"change" column is excluded because it has no useful data unless --all is
specified.

--- 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():