Upstream changes (from CHANGELOG.md):
## 1.10.0 / 2019-01-04
### Features
* [MRI] Cross-built Windows gems now support Ruby 2.6 [#1842, #1850]
### Backwards incompatibilities
This release ends support for:
* Ruby 2.2, for which [official support ended on 2018-03-31](https://www.ruby-lang.org/en/news/2018/06/20/support-of-ruby-2-2-has-ended/) [#1841]
* JRuby 1.7, for which [official support ended on 2017-11-21](https://github.com/jruby/jruby/issues/4112) [#1741]
### Dependencies
* [MRI] libxml2 is updated from 2.9.8 to 2.9.9
* [MRI] libxslt is updated from 1.1.32 to 1.1.33
## 1.9.1 / 2018-12-17
### Bug fixes
* Fix a bug introduced in v1.9.0 where `XML::DocumentFragment#dup` no longer returned an instance of the callee's class, instead always returning an `XML::DocumentFragment`. This notably broke any subclass of `XML::DocumentFragment` including `HTML::DocumentFragment` as well as the Loofah gem's `Loofah::HTML::DocumentFragment`. [#1846]
## 1.9.0 / 2018-12-17
### Security Notes
* [JRuby] Upgrade Xerces dependency from 2.11.0 to 2.12.0 to address upstream vulnerability CVE-2012-0881 [#1831] (Thanks @grajagandev for reporting.)
### Notable non-functional changes
* Decrease installation size by removing many unneeded files (e.g., `/test`) from the packaged gems. [#1719] (Thanks, @stevecrozz!)
### Features
* `XML::Attr#value=` allows HTML node attribute values to be set to either a blank string or an empty boolean attribute. [#1800]
* Introduce `XML::Node#wrap` which does what `XML::NodeSet#wrap` has always done, but for a single node. [#1531] (Thanks, @ethirajsrinivasan!)
* [MRI] Improve installation experience on macOS High Sierra (Darwin). [#1812, #1813] (Thanks, @gpakosz and @nurse!)
* [MRI] Node#dup supports copying a node directly to a new document. See the method documentation for details.
* [MRI] DocumentFragment#dup is now more memory-efficient, avoiding making unnecessary copies. [#1063]
* [JRuby] NodeSet has been rewritten to improve performance! [#1795]
### Bug fixes
* `NodeSet#each` now returns `self` instead of zero. [#1822] (Thanks, @olehif!)
* [MRI] Address a memory leak when using XML::Builder to create nodes with namespaces. [#1810]
* [MRI] Address a memory leak when unparenting a DTD. [#1784] (Thanks, @stevecheckoway!)
* [MRI] Use RbConfig::CONFIG instead of ::MAKEFILE_CONFIG to fix installations that use Makefile macros. [#1820] (Thanks, @nobu!)
* [JRuby] Decrease large memory usage when making nested XPath queries. [#1749]
* [JRuby] Fix failing tests on JRuby 9.2.x
* [JRuby] Fix default namespaces in nodes reparented into a different document [#1774]
* [JRuby] Fix support for Java 9. [#1759] (Thanks, @Taywee!)
### Dependencies
* [MRI] Upgrade mini_portile2 dependency from `~> 2.3.0` to `~> 2.4.0`
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