template-phases: do not show description or summary if empty

This is a copy of c1cb6523e968, but applied to the phases template,
which is itself almost a copy of the default template.

Perhaps we should rewrite these templates to use the %include syntax
afforded by config files. This change seems a bit too big for stable,
though.

mercurial/templates/map-cmdline.phases

@@ -58,8 +58,8 b' bookmark = \'{label("log.bookmark",'
 user = '{label("log.user",
                "user:        {author}")}\n'
 
-summary = '{label("log.summary",
-                  "summary:     {desc|firstline}")}\n'
+summary = '{if(desc|strip, "{label('log.summary',
+                                   'summary:     {desc|firstline}')}\n")}'
 
 ldate = '{label("log.date",
                 "date:        {date|date}")}\n'
@@ -67,7 +67,7 b' ldate = \'{label("log.date",'
 extra = '{label("ui.debug log.extra",
                 "extra:       {key}={value|stringescape}")}\n'
 
-description = '{label("ui.note log.description",
-                       "description:")}
-               {label("ui.note log.description",
-                       "{desc|strip}")}\n\n'
+description = '{if(desc|strip, "{label('ui.note log.description',
+                                       'description:')}
+                                {label('ui.note log.description',
+                                       '{desc|strip}')}\n\n")}'

tests/test-command-template.t

@@ -101,23 +101,52 b' following below omit it properly.'
   $ hg add c
   $ hg commit -qm ' '
 
-Default style is like normal output.
+Default style is like normal output. Phases style should be the same
+as default style, except for extra phase lines.
 
   $ hg log > log.out
   $ hg log --style default > style.out
   $ cmp log.out style.out || diff -u log.out style.out
+  $ hg log -T phases > phases.out
+  $ diff -u log.out phases.out | grep "phase:"
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
 
   $ hg log -v > log.out
   $ hg log -v --style default > style.out
   $ cmp log.out style.out || diff -u log.out style.out
+  $ hg log -v -T phases > phases.out
+  $ diff -u log.out phases.out | grep phase:
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
+  +phase:       draft
 
   $ hg log -q > log.out
   $ hg log -q --style default > style.out
   $ cmp log.out style.out || diff -u log.out style.out
+  $ hg log -q -T phases > phases.out
+  $ cmp log.out phases.out || diff -u log.out phases.out
 
   $ hg log --debug > log.out
   $ hg log --debug --style default > style.out
   $ cmp log.out style.out || diff -u log.out style.out
+  $ hg log --debug -T phases > phases.out
+  $ cmp log.out phases.out || diff -u log.out phases.out
 
 Default style should also preserve color information (issue2866):
 
@@ -130,15 +159,46 b' Default style should also preserve color'
   $ hg --color=debug log > log.out
   $ hg --color=debug log --style default > style.out
   $ cmp log.out style.out || diff -u log.out style.out
+  $ hg --color=debug log -T phases > phases.out
+  $ diff -u log.out phases.out | grep phase:
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+
   $ hg --color=debug -v log > log.out
   $ hg --color=debug -v log --style default > style.out
   $ cmp log.out style.out || diff -u log.out style.out
+  $ hg --color=debug -v log -T phases > phases.out
+  $ diff -u log.out phases.out | grep phase:
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+  +[log.phase|phase:       draft]
+
   $ hg --color=debug -q log > log.out
   $ hg --color=debug -q log --style default > style.out
   $ cmp log.out style.out || diff -u log.out style.out
+  $ hg --color=debug -q log -T phases > phases.out
+  $ cmp log.out phases.out || diff -u log.out phases.out
+
   $ hg --color=debug --debug log > log.out
   $ hg --color=debug --debug log --style default > style.out
   $ cmp log.out style.out || diff -u log.out style.out
+  $ hg --color=debug --debug log -T phases > phases.out
+  $ cmp log.out phases.out || diff -u log.out phases.out
 
   $ mv $HGRCPATH-bak $HGRCPATH