revset: prevent crash caused by empty group expression while optimizing "and"
An empty group expression "()" generates None in AST, so the optimizer have
to test it before destructuring a tuple. The error message, "missing argument",
is somewhat obscure, but it should be better than crash.
{header}
<title>{repo|escape}: changelog</title>
<link rel="alternate" type="application/atom+xml" href="{url|urlescape}atom-log" title="Atom feed for {repo|escape}"/>
<link rel="alternate" type="application/rss+xml" href="{url|urlescape}rss-log" title="RSS feed for {repo|escape}"/>
</head>
<body>
<div id="container">
<div class="page-header">
<h1 class="breadcrumb"><a href="/">Mercurial</a> {pathdef%breadcrumb} / changelog</h1>
<form action="{url|urlescape}log">
{sessionvars%hiddenformentry}
<dl class="search">
<dt><label>Search: </label></dt>
<dd><input type="text" name="rev" /></dd>
</dl>
</form>
<ul class="page-nav">
<li><a href="{url|urlescape}summary{sessionvars%urlparameter}">summary</a></li>
<li><a href="{url|urlescape}shortlog{sessionvars%urlparameter}">shortlog</a></li>
<li class="current">changelog</li>
<li><a href="{url|urlescape}graph/{symrev}{sessionvars%urlparameter}">graph</a></li>
<li><a href="{url|urlescape}tags{sessionvars%urlparameter}">tags</a></li>
<li><a href="{url|urlescape}bookmarks{sessionvars%urlparameter}">bookmarks</a></li>
<li><a href="{url|urlescape}branches{sessionvars%urlparameter}">branches</a></li>
<li><a href="{url|urlescape}file/{symrev}{sessionvars%urlparameter}">files</a></li>
{archives%archiveentry}
<li><a href="{url|urlescape}help{sessionvars%urlparameter}">help</a></li>
</ul>
</div>
<h2 class="no-link no-border">changelog</h2>
<div>
{entries%changelogentry}
</div>
<div class="page-path">
{changenav%nav}
</div>
{footer}