hgweb: descend empty directories in web view
When a manifest has a series of directories with nothing in them but a single
directory, displaying the entire chain of empty directories allows for
navigation down to the first non-empty directory with a single click.
Because Java links package hierarchy to directory hierarchy, and because Java
conventions include at least three empty directories at the top of this
hierarchy, descending down empty directories is very common in Java web tools.
% Set up the repo
adding a1/a2/a3/a4/foo
adding b1/b2/b3/b4/foo
adding b1/b2/c3/c4/foo
adding d1/d2/d3/d4/foo
adding d1/d2/foo
% manifest with descending
200 Script output follows
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<link rel="icon" href="/static/hgicon.png" type="image/png">
<meta name="robots" content="index, nofollow" />
<link rel="stylesheet" href="/static/style.css" type="text/css" />
<title>test: files for changeset 9087c84a0f5d</title>
</head>
<body>
<div class="buttons">
<a href="/log/0">changelog</a>
<a href="/shortlog/0">shortlog</a>
<a href="/graph">graph</a>
<a href="/tags">tags</a>
<a href="/rev/9087c84a0f5d">changeset</a>
</div>
<h2>files for changeset 9087c84a0f5d: /</h2>
<table cellpadding="0" cellspacing="0">
<tr class="parity0">
<td><tt>drwxr-xr-x</tt>
<td>
<td>
<td><a href="/file/9087c84a0f5d/">[up]</a>
</tr>
<tr class="parity1"><td><tt>drwxr-xr-x</tt> <td> <td> <td><a href="/file/9087c84a0f5d/a1">a1/</a> <a href="/file/9087c84a0f5d/a1/a2/a3/a4">a2/a3/a4</a><tr class="parity0"><td><tt>drwxr-xr-x</tt> <td> <td> <td><a href="/file/9087c84a0f5d/b1">b1/</a> <a href="/file/9087c84a0f5d/b1/b2">b2</a><tr class="parity1"><td><tt>drwxr-xr-x</tt> <td> <td> <td><a href="/file/9087c84a0f5d/d1">d1/</a> <a href="/file/9087c84a0f5d/d1/d2">d2</a>
</table>
<div class="logo">
<a href="http://www.selenic.com/mercurial/">
<img src="/static/hglogo.png" width=75 height=90 border=0 alt="mercurial"></a>
</div>
</body>
</html>
% ERRORS ENCOUNTERED