error message: unknown state: :push! when using velocity.rb

[domRowan]

Name of the lexer
velocity.rb

Code sample
A diff to apply to spec/visual/samples/velocity to expose this issue whilst running bundle exec rake

diff --git a/spec/visual/samples/velocity b/spec/visual/samples/velocity
index 644a677d..2ebc45ad 100644
--- a/spec/visual/samples/velocity
+++ b/spec/visual/samples/velocity
@@ -25,4 +25,4 @@ ${customer.Address}
 ${purchase.getTotal(true)}
 $title.set( "Homage to Catalonia" )
 
-
+#set( $result = $foo($bar[$baz]) )

Additional context

Looks like this issue is caused by the use of [ within nested parenthesis.
The smallest possible snippet that will reproduce the issue is #set(([])).

Looks like this is a result of this rule using push! instead of push:

rouge/lib/rouge/lexers/velocity.rb

Line 66 in 128abf0

rule %r/[(\[]/, Punctuation, :push!

Further work

I have identified that a similar issue MAY be present in ceylon.rb

rouge/lib/rouge/lexers/ceylon.rb

Line 90 in 1af45d5

rule %r(/\*), Comment::Multiline, :push!

[domRowan]

PR to fix velocity lexer here: #1605