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Correct Binding#dup to properly propagate values it captures#7688

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enebo merged 8 commits intojruby:masterfrom
enebo:weird_binding
May 2, 2024
Merged

Correct Binding#dup to properly propagate values it captures#7688
enebo merged 8 commits intojruby:masterfrom
enebo:weird_binding

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@enebo enebo commented Feb 23, 2023 •
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Binding#dup will get all variables from the original binding but when new ones are added to the new dup the old binding will not see them. This is a more broken down spec for the behavior:

  it "retains original binding variables but the list is distinct" do
    bind1 = binding
    eval "a = 1", bind1

    bind2 = bind1.dup
    eval("a = 2", bind2)
    eval("a", bind1).should == 2
    eval("a", bind2).should == 2

    eval("b = 2", bind2)
    -> { eval("b", bind1) }.should raise_error(NameError)
    eval("b", bind2).should == 2
    
    bind1.local_variables.sort.should == [:a, :bind1, :bind2]
    bind2.local_variables.sort.should == [:a, :b, :bind1, :bind2]
  end

This fixes the last two errors involving specs in erb. I added this spec to make the behavior explicit and not appear to be some artifact of erb.

@enebo
Try and appease the eval+binding gods
f304def 
When we eval with binding we will construct a new binding that
contains the original binding and that original binding will
construct a new evalDynamicScope.  If I do something like:

```ruby
p TOPLEVEL_BINDING.local_variable_defined? :c
p TOPLEVEL_BINDING.local_variable_defined? :_xxx_var_

b =TOPLEVEL_BINDING.dup
p b.local_variable_defined? :c
p b.local_variable_defined? :_xxx_var_
```

I should still see _xxx_var_ after the dup.  This will make that
do that but two different RubyBinding instances will end up
with the exact same backing Binding and I think this is wrong.
Landing anyways to see if anything breaks.
@enebo enebo added this to the JRuby 9.4.2.0 milestone Feb 23, 2023
@enebo enebo removed this from the JRuby 9.4.2.0 milestone Mar 8, 2023
@enebo enebo changed the title Try and appease the eval+binding gods Correct Binding#dup to properly propagate values it captures May 2, 2024
@enebo enebo added this to the JRuby 9.4.8.0 milestone May 2, 2024
@enebo enebo merged commit 540f511 into jruby:master May 2, 2024
@enebo enebo deleted the weird_binding branch March 4, 2025 18:32
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