DOMDocument is enabled by default, but can be disabled with --disable-dom, or by an overzealous distro. This poses serious problems for widely distributed/deployed software that uses SimplePie and needs to work on as many environments as possible.
Was not a problem with SimplePie 1.2.
Downstream: http://core.trac.wordpress.org/ticket/21990. This is a blocker for WordPress.
Generate an error if DOMDocument doesn't exist
Rather than trying to load the class and getting a failure, this much more
sensibly generates an error. Fixes #241
Also introduces SimplePie_Exception, which is only used internally.
This is still occurring, as one instance of this was missed.
If DOMDocument doesn't exist, nicely fail Sanitize
See #241. This fixes it for 1.3.2, but requires different changes for 1.4.
Handle DOMDocument errors nicely when sanitizing
Fixes #241 for 1.4. Also introduces SimplePie::enable_exceptions() for better
error handling via progessive enhancement.