clone.diff

diff --git a/Changes b/Changes
index d508b80..84af113 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,7 @@
 
 6.26  2015-10-23
+  - Improved performance of DOM manipulation methods in Mojo::DOM significantly
+    when working with existing Mojo::DOM objects.
 
 6.25  2015-10-21
   - Deprecated Mojo::Message::Request::proxy with boolean and string arguments
diff --git a/lib/Mojo/DOM.pm b/lib/Mojo/DOM.pm
index 2bda8b1..39ff943 100644
--- a/lib/Mojo/DOM.pm
+++ b/lib/Mojo/DOM.pm
@@ -15,6 +15,7 @@ use Mojo::DOM::CSS;
 use Mojo::DOM::HTML;
 use Mojo::Util 'squish';
 use Scalar::Util qw(blessed weaken);
+use Storable 'dclone';
 
 sub all_text { shift->_all_text(1, @_) }
 
@@ -280,7 +281,17 @@ sub _offset {
 
 sub _parent { $_[0]->tree->[$_[0]->type eq 'tag' ? 3 : 2] }
 
-sub _parse { Mojo::DOM::HTML->new(xml => shift->xml)->parse(shift)->tree }
+sub _parse {
+  my ($self, $html) = @_;
+
+  return Mojo::DOM::HTML->new(xml => $self->xml)->parse($html)->tree
+    unless blessed $html && $html->isa('Mojo::DOM');
+
+  my $clone = dclone $html->tree;
+  return $clone if $clone->[0] eq 'root';
+  _link(['root', $clone], my $parent = ['root', $clone]);
+  return $parent;
+}
 
 sub _replace {
   my ($self, $parent, $tree, $new) = @_;
@@ -499,6 +510,7 @@ All selectors from L<Mojo::DOM::CSS/"SELECTORS"> are supported.
 
 =head2 append
 
+  $dom = $dom->append(Mojo::DOM->new);
   $dom = $dom->append('<p>I ♥ Mojolicious!</p>');
 
 Append HTML/XML fragment to this node.
@@ -513,6 +525,7 @@ Append HTML/XML fragment to this node.
 
 =head2 append_content
 
+  $dom = $dom->append_content(Mojo::DOM->new);
   $dom = $dom->append_content('<p>I ♥ Mojolicious!</p>');
 
 Append HTML/XML fragment (for C<root> and C<tag> nodes) or raw content to this
@@ -583,6 +596,7 @@ All selectors from L<Mojo::DOM::CSS/"SELECTORS"> are supported.
 =head2 content
 
   my $str = $dom->content;
+  $dom    = $dom->content(Mojo::DOM->new);
   $dom    = $dom->content('<p>I ♥ Mojolicious!</p>');
 
 Return this node's content or replace it with HTML/XML fragment (for C<root>
@@ -766,6 +780,7 @@ node as L<Mojo::DOM> objects.
 
 =head2 prepend
 
+  $dom = $dom->prepend(Mojo::DOM->new);
   $dom = $dom->prepend('<p>I ♥ Mojolicious!</p>');
 
 Prepend HTML/XML fragment to this node.
@@ -780,6 +795,7 @@ Prepend HTML/XML fragment to this node.
 
 =head2 prepend_content
 
+  $dom = $dom->prepend_content(Mojo::DOM->new);
   $dom = $dom->prepend_content('<p>I ♥ Mojolicious!</p>');
 
 Prepend HTML/XML fragment (for C<root> and C<tag> nodes) or raw content to this
@@ -836,6 +852,7 @@ Remove this node and return L</"root"> (for C<root> nodes) or L</"parent">.
 
 =head2 replace
 
+  my $parent = $dom->replace(Mojo::DOM->new);
   my $parent = $dom->replace('<div>I ♥ Mojolicious!</div>');
 
 Replace this node with HTML/XML fragment and return L</"root"> (for C<root>
@@ -970,6 +987,7 @@ if none could be found.
 
 =head2 wrap
 
+  $dom = $dom->wrap(Mojo::DOM->new);
   $dom = $dom->wrap('<div></div>');
 
 Wrap HTML/XML fragment around this node, placing it as the last child of the
@@ -989,6 +1007,7 @@ first innermost element.
 
 =head2 wrap_content
 
+  $dom = $dom->wrap_content(Mojo::DOM->new);
   $dom = $dom->wrap_content('<div></div>');
 
 Wrap HTML/XML fragment around this node's content, placing it as the last
diff --git a/t/mojo/dom.t b/t/mojo/dom.t
index b6c01a9..8f9d058 100644
--- a/t/mojo/dom.t
+++ b/t/mojo/dom.t
@@ -462,7 +462,7 @@ $dom = Mojo::DOM->new('<div>foo<p>lalala</p>bar</div>');
 is $dom->at('p')->replace('<foo>bar</foo>'), '<div>foo<foo>bar</foo>bar</div>',
   'right result';
 is "$dom", '<div>foo<foo>bar</foo>bar</div>', 'right result';
-$dom->at('foo')->replace(Mojo::DOM->new('text'));
+$dom->at('foo')->replace(Mojo::DOM->new('text')->child_nodes->first);
 is "$dom", '<div>footextbar</div>', 'right result';
 $dom = Mojo::DOM->new('<div>foo</div><div>bar</div>');
 $dom->find('div')->each(sub { shift->replace('<p>test</p>') });
@@ -490,7 +490,8 @@ is $dom->at('div')->replace('<p>♥</p>')->root, '<p>♥</p>', 'right result';
 is $dom->to_string, '<p>♥</p>', 'right result';
 is $dom->replace('<b>whatever</b>')->root, '<b>whatever</b>', 'right result';
 is $dom->to_string, '<b>whatever</b>', 'right result';
-$dom->at('b')->prepend('<p>foo</p>')->append('<p>bar</p>');
+$dom->at('b')->prepend(Mojo::DOM->new('<p>foo</p>')->at('p'))
+  ->append(Mojo::DOM->new('<p>bar</p>')->at('p'));
 is "$dom", '<p>foo</p><b>whatever</b><p>bar</p>', 'right result';
 is $dom->find('p')->map('remove')->first->root->at('b')->text, 'whatever',
   'right result';
@@ -1268,7 +1269,8 @@ is "$dom", <<EOF, 'right result';
 </ul>
 <div>D</div>works
 EOF
-$dom->at('li')->prepend_content('A3<p>A2</p>')->prepend_content('A4');
+$dom->at('li')->prepend_content('A3<p>A2</p>')
+  ->prepend_content(Mojo::DOM->new('A4')->child_nodes->first);
 is $dom->at('li')->text, 'A4A3 A', 'right text';
 is "$dom", <<EOF, 'right result';
 <ul>
@@ -2100,7 +2102,8 @@ is $dom->wrap('<b></b>')->type, 'root', 'right type';
 is "$dom", '<b><a>Test</a></b>', 'right result';
 is $dom->at('b')->strip->at('a')->wrap('A')->tag, 'a', 'right tag';
 is "$dom", '<a>Test</a>', 'right result';
-is $dom->at('a')->wrap('<b></b>')->tag, 'a', 'right tag';
+is $dom->at('a')->wrap(Mojo::DOM->new('<b></b>')->at('b'))->tag, 'a',
+  'right tag';
 is "$dom", '<b><a>Test</a></b>', 'right result';
 is $dom->at('a')->wrap('C<c><d>D</d><e>E</e></c>F')->parent->tag, 'd',
   'right tag';
@@ -2110,7 +2113,8 @@ is "$dom", '<b>C<c><d>D<a>Test</a></d><e>E</e></c>F</b>', 'right result';
 $dom = Mojo::DOM->new('<a>Test</a>');
 is $dom->at('a')->wrap_content('A')->tag, 'a', 'right tag';
 is "$dom", '<a>Test</a>', 'right result';
-is $dom->wrap_content('<b></b>')->type, 'root', 'right type';
+is $dom->wrap_content(Mojo::DOM->new('<b></b>')->at('b'))->type, 'root',
+  'right type';
 is "$dom", '<b><a>Test</a></b>', 'right result';
 is $dom->at('b')->strip->at('a')->tag('e:a')->wrap_content('1<b c="d"></b>')
   ->tag, 'e:a', 'right tag';
@@ -2440,7 +2444,7 @@ is $dom->at('  :not(  #foo  )  ')->text, 'works', 'right text';
 # "0"
 $dom = Mojo::DOM->new('0');
 is "$dom", '0', 'right result';
-$dom->append_content('☃');
+$dom->append_content(Mojo::DOM->new('☃')->child_nodes->first);
 is "$dom", '0☃', 'right result';
 is $dom->parse('<!DOCTYPE 0>'),  '<!DOCTYPE 0>',  'successful roundtrip';
 is $dom->parse('<!--0-->'),      '<!--0-->',      'successful roundtrip';