Issue #11566 has been reported by D.E. Akers.

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Bug #11566: Segfault when enumerating from a bad constructor. 
https://bugs.ruby-lang.org/issues/11566

* Author: D.E. Akers
* Status: Open
* Priority: Normal
* Assignee: 
* ruby -v: ruby 2.3.0dev (2015-10-04 trunk 52020) [x86_64-linux]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
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```ruby
Enumerator.new(&:foo).to_a
```

This should raise a `NoMethodError` as it does for older Rubies, but the recent modifications to the internals of `Symbol#to_proc` seem to have elided the CFP information necessary to realize the `NME`.

I've attached a core dump which ultimately blames the `VM_EP_LEP_P()` macro for dereferencing a null pointer.

``` c
#define VM_EP_LEP_P(ep)     VM_ENVVAL_BLOCK_PTR_P((ep)[0])
```

Aside from observing that the block must not have an "environment" where it expected to find one, I am regrettably unable to provide any further information as to the nature or mitigation of this issue.

---Files--------------------------------
core (3.96 KB)


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