Bug #21776: Binding#local_variable_defined? still supports numbered parameters

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 4.0.0dev (2025-12-11T18:57:06Z master d02c971574) +PRISM [x86_64-linux]
• Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN

[zverok (Victor Shepelev)]

On the freshest master:

[1].each {_1; p binding.local_variable_defined?(:_1) }
#=> true

It is inconsistent with changes in #local_variables/#local_variable_get/#local_variable_set. And inconsistent with handling of it:

[1].each { it; p binding.local_variable_defined?(:it) }
#=> false

[mame (Yusuke Endoh)]

Thanks! https://github.com/ruby/ruby/pull/15519 will fix the issue.

[mame (Yusuke Endoh)]

• Status changed from Open to Closed

Applied in changeset git|04494d9e4064a57accc8309da9b35754a3d24973.

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Binding#local_variable_defined? must not handle numbered parameters

[Bug #21776]

[mame (Yusuke Endoh)]

I noticed that binding.local_variable_defined?(:@x) raises wrong local variable name '@x' for #<Binding:0x00007cd1e95a94d8> (NameError).
Maybe binding.local_variable_defined?(:_1) should raise a similar error because _1 is not a local variable. I will create a PR.

[mame (Yusuke Endoh)]

• Status changed from Closed to Open

[mame (Yusuke Endoh)]

• Status changed from Open to Closed

Applied in changeset git|1794cfe12fe61dedebadead542927f9fef4104eb.

---

Binding#local_variable_defined? raises a NameError for numbered params.

[Bug #21776]