copies: do not track backward copies, only renames (issue3739)
The inverse of a rename is a rename, but the inverse of a copy is not a copy.
Presenting it as such -- in particular, stuffing it into the same dict as real
copies -- causes bugs because other code starts believing the inverse copies
are real.
The only test whose output changes is test-mv-cp-st-diff.t. When a backwards
status -C command is run where a copy is involved, the inverse copy (which was
hitherto presented as a real copy) is no longer displayed.
Keeping track of inverse copies is useful in some situations -- composability
of diffs, for example, since adding "a" followed by an inverse copy "b" to "a"
is equivalent to a rename "b" to "a". However, representing them would require
a more complex data structure than the same dict in which real copies are also
stored.
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<!-- This is the second screen displayed during the install. -->
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta http-equiv="Content-Style-Type" content="text/css">
<title></title>
<style type="text/css">
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Helvetica}
p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; min-height: 14.0px}
p.p3 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica}
p.p4 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; color: #000fed}
span.s1 {text-decoration: underline}
span.s2 {font: 12.0px Courier}
</style>
</head>
<body>
<p class="p1"><b>Before you install</b></p>
<p class="p2"><br></p>
<p class="p3">This is an OS X 10.6 version of Mercurial that depends on the default Python 2.6 installation.</p>
<p class="p2"><br></p>
<p class="p1"><b>After you install</b></p>
<p class="p2"><br></p>
<p class="p3">This package installs the <span class="s2">hg</span> executable in <span class="s2">/usr/local/bin</span> and the Mercurial files in <span class="s2">/Library/Python/2.6/site-packages/mercurial.</span></p>
<p class="p2"><br></p>
<p class="p1"><b>Documentation</b></p>
<p class="p2"><br></p>
<p class="p3">Visit the <a href="http://mercurial.selenic.com/">Mercurial web site and wiki</a></p>
<p class="p2"><br></p>
<p class="p3">There's also a free book, <a href="http://hgbook.red-bean.com/">Distributed revision control with Mercurial</a></p>
<p class="p2"><br></p>
<p class="p1"><b>Reporting problems</b></p>
<p class="p2"><br></p>
<p class="p3">If you run into any problems, please file a bug online:</p>
<p class="p3"><a href="http://mercurial.selenic.com/bts/">http://mercurial.selenic.com/bts/</a></p>
</body>
</html>