Fix ancestry for unattached nodes

Fixes issue 1092.

Unattached nodes have no className, so their className
never matched idClass, which made domita think that
the parent belonged to some other gadget.  I added a
check to return null if we hit document.body (i.e.
it really does belong to another gadget) and added
code to return the parnet node if it exits the loop
(i.e. it's unattached).

[ihab.awad, 2009-08-01 00:55:34]

LGTM

[MikeSamuel, 2009-08-01 01:02:48]

http://codereview.appspot.com/98088/diff/1/2
File src/com/google/caja/plugin/domita.js (right):

http://codereview.appspot.com/98088/diff/1/2#newcode1056
Line 1056: } else if (ancestor === document.body) {
Instead of using document, please use node.ownerDocument.documentElement instead
of document.body since this will currently allow access to the head, title, and
other elements in the document outside the body.

Maybe use contains/compareDocumentPosition to check whether the node is
contained.

[metaweta, 2009-08-01 01:10:25]

On 2009/08/01 01:02:48, MikeSamuel wrote:
> http://codereview.appspot.com/98088/diff/1/2
> File src/com/google/caja/plugin/domita.js (right):
> 
> http://codereview.appspot.com/98088/diff/1/2#newcode1056
> Line 1056: } else if (ancestor === document.body) {
> Instead of using document, please use node.ownerDocument.documentElement
instead
> of document.body since this will currently allow access to the head, title,
and
> other elements in the document outside the body.

Done.

[felix8a, 2009-08-01 01:16:25]

http://codereview.appspot.com/98088/diff/1002/7
File src/com/google/caja/plugin/domita.js (right):

http://codereview.appspot.com/98088/diff/1002/7#newcode1056
Line 1056: } else if (ancestor === node.ownerDocument.documentElement) {
could you hoist node.ownerDocument.documentElement
outside the loop?  traversing properties of dom nodes is slow.

[metaweta, 2009-08-01 01:32:45]

On 2009/08/01 01:02:48, MikeSamuel wrote:
> Maybe use contains/compareDocumentPosition to check whether the node is
> contained.

Yeah, we could check if it's contained by node.ownerDocument.documentElement
first instead of last, but then every parentNode lookup would pay the price of
checking containment.

Which is the more common case?

[metaweta, 2009-08-01 01:33:55]

On 2009/08/01 01:16:25, felix8a wrote:
> http://codereview.appspot.com/98088/diff/1002/7
> File src/com/google/caja/plugin/domita.js (right):
> 
> http://codereview.appspot.com/98088/diff/1002/7#newcode1056
> Line 1056: } else if (ancestor === node.ownerDocument.documentElement) {
> could you hoist node.ownerDocument.documentElement
> outside the loop?  traversing properties of dom nodes is slow.

Done.

[metaweta, 2009-08-03 18:50:32]

@3628