Ugly inconsistence betw. for and for/in

Hi there,

I've just bumped into the problem that the c-like for properly scopes/does not scope based on whether its control variable is declared or just used, whilst for/in always scopes, regardless the form (see the example below for detailed explanation).

Is this a bug or an intended behaviour?

It would be nice to fix it so that for/in does not scope when there's no declaration, but I fear it might be a breaking change for legacy code :(

Thanks and all the best,
OC

===
5 ocs /tmp> <q.groovy 
class Foo {
  def foo
  def bar() { println "foo='$foo'" }
  def test() {
    println "Should not change"
    for (def foo in [1,2]) bar()
    println "Precisely like does not here"
    for (def foo=1; foo<3; foo++) bar()
    println "Should change but does not"
    for (foo in [1,2]) bar()
    println "Precisely like does here"
    for (foo=1; foo<3; foo++) bar()
  }
  static main(args) {
    Foo.newInstance().test()
  }
}
6 ocs /tmp> groovy q 
Should not change
foo='null'
foo='null'
Precisely like does not here
foo='null'
foo='null'
Should change but does not
foo='null'
foo='null'
Precisely like does here
foo='1'
foo='2'
7 ocs /tmp> groovy -version
Groovy Version: 4.0.27 JVM: 1.8.0_452 Vendor: Tencent OS: Mac OS X
8 ocs /tmp>