[ruby-core:71653] [Ruby trunk - Bug #8543] new rb_iseq_load crash

Issue #8543 has been updated by Tomoyuki Chikanaga.

Backport changed from 2.0.0: UNKNOWN, 2.1: REQUIRED, 2.2: REQUIRED to 2.0.0: UNKNOWN, 2.1: REQUIRED, 2.2: DONE

Backported into `ruby_2_2` branch at r52740.

----------------------------------------
Bug #8543: new rb_iseq_load crash
https://bugs.ruby-lang.org/issues/8543#change-55058

* Author: Alexey Voskov
* Status: Closed
* Priority: Normal
* Assignee: Koichi Sasada
* ruby -v: -
* Backport: 2.0.0: UNKNOWN, 2.1: REQUIRED, 2.2: DONE
----------------------------------------
I noticed an unusual behaviour of undocumented rb_iseq_load function. 
Its work differs in different Ruby versions. I'm trying to protect some Ruby
source code by its conversion to YARV p-code and using the next strategy:

1. Convert code to array

   ~~~ruby
   data = RubyVM::InstructionSequence.compile_file('hello.rb').to_a
   ~~~

2. Pass a compiled source to the rb_iseq_load function and evaluate it

   ~~~ruby
   iseq = iseq_load.(data)
   iseq.eval
   ~~~

Sample programs are supplied in the attachments.
"hello.rb"

```ruby
puts "tralivali"
def funct(a,b)
  a**b
end

3.times { |i|
  puts "Hello, world#{funct(2,i)}!"
}
```

The differences
Ruby 1.9.3 (ruby 1.9.3p194 (2012-04-20) [i386-mingw32])
Correct work. Output:

```
tralivali
Hello, world1!
Hello, world2!
Hello, world4!
```

Ruby 2.0.0 (ruby 2.0.0p193 (2013-05-14) [x64-mingw32])
Incorrect work (omits the code inside code blocks). Output

```
tralivali
```

Attempts of loading bigger programs by means of rb_iseq_load in Ruby 2.0.0 usually ends with a segmentation fault.

Such behaviour also can be reproduced by means of iseq Ruby extension ("for iseq freaks")
https://github.com/wanabe/iseq

P.S. I understand that it is an undocumented feature.


---Files--------------------------------
hello.rb (102 Bytes)
rb_pack.rb (931 Bytes)
iseq-load-test3.rb (210 Bytes)
iseq-load-test3-file.rb (369 Bytes)
please-fix-rb_iseq_load-thank-you.pdf (444 KB)
iseq-load-test5.rb (4.7 KB)


-- 
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