[ruby-core:117710] [Ruby master Bug#20455] rb_errinfo() inconsistent with $! in the caller Ruby code

["Eregon (Benoit Daloze) via ruby-core" <ruby-core@ml.ruby-lang.org>]

Issue #20455 has been reported by Eregon (Benoit Daloze).

----------------------------------------
Bug #20455: rb_errinfo() inconsistent with $! in the caller Ruby code
https://bugs.ruby-lang.org/issues/20455

* Author: Eregon (Benoit Daloze)
* Status: Open
* ruby -v: ruby 3.4.0dev (2024-04-25T08:12:47Z master 64bd8e41df) [x86_64-linux]
* Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN
----------------------------------------
This (slightly modified for clarity) test in ruby/spec demonstrates the unexpected result:
```ruby
  describe "rb_errinfo" do
    def err
      $!
    end

    it "is cleared when entering a C method" do
      begin
        raise StandardError
      rescue
        $!.class.should == StandardError
        err.class.should == StandardError
        @s.rb_errinfo().should == nil
      end
    end
```

Why does `rb_errinfo()` return nil there, when $! is set in the caller (and $! isn't per frame but per thread, as shown with `err`)?

Is this bug?
If not, what is the logic and reason for clearing `$!` when calling a method defined in C?



-- 
https://bugs.ruby-lang.org/
 ______________________________________________
 ruby-core mailing list -- ruby-core@ml.ruby-lang.org
 To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org
 ruby-core info -- https://ml.ruby-lang.org/mailman3/postorius/lists/ruby-core.ml.ruby-lang.org/