This fix is slightly hackish, as we simply treat comments as whitespace.
This should largely be correct, and breaks no current test cases,
although it could result in noncompliant behavior.
Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>
Injector rewind: Injectors can now use the method rewind() in order to move
the input index backwards, so that they can reprocess tokens (other injectors
are not affected by a rewind). This functionality was necessary to implement
nested node removals in %AutoFormat.RemoveEmpty.
End to start ref: To facilitate rewinding, HTMLPurifier_Token_End now
maintains a reference called $start to the starting token for their node.
%AutoFormat.RemoveEmpty removes empty nodes. Lots of people have requested
it, so here is a partially effective implementation. Because it is implemented
as an Injector, it's not possible for it to handle newly introduced empty
nodes by later validators, specifically auto-closing and child validation.
The Injector is only meant to be used on HTML-ish languages.
Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>
