Bug #730: Infinite recursion on 'super' in dynamically generated modules

• Status: Closed
• Assignee: ko1 (Koichi Sasada)
• Target version: 1.9.1 Release Candidate

[sander (Sander Land)]

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Note:
Bug reported earlier (2007-12-21) on rubyforge, but still exists in 1.9.1
More detailed description at:
http://rubyforge.org/tracker/?func=detail&atid=1698&aid=16493&group_id=426
and
http://pastie.org/132996

Take the following test case:

def genmod
Module.new{
def foo
super
end
}
end

mod = genmod
mod2= genmod # comment this line to stop infinite recursion and get a (correct) 'no superclass method' error.
klass = Class.new{ include mod }
klass.new.foo # infinite recursion

This causes:

smallbug19.rb:4:in foo': stack level too deep (SystemStackError) from smallbug19.rb:4:in foo'
from smallbug19.rb:4:in foo' from smallbug19.rb:4:in foo'
from smallbug19.rb:4:in `foo'
etc.

So somehow the module is considered its own superclass, after multiple calls to a function that generates modules.
Everything is alright after the first call, but after the second call the module generated in the first call somehow breaks.

See the links above, especially the pastie link, and attached files for some test cases and old attempts to track it down in the 1.9.0 C code.

Ruby 1.8.x does not have this bug, and (as far as I know) all 1.9.x versions do.
=end

[nobu (Nobuyoshi Nakada)]

• Assignee set to ko1 (Koichi Sasada)

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=end

[yugui (Yuki Sonoda)]

• Priority changed from Normal to 5

=begin
Fix this soon. < ko1
=end

[antares (Michael Klishin)]

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What is interesting, if you include mod2 instead of mod in the code snippet above, there is no stack overflow.
=end

[antares (Michael Klishin)]

=begin
Even more interesting stuff pops up after some investigation: adding one of the following lines right before calling foo on instance of anonymous class makes the problem go away:

#puts mod.method(:foo).inspect
#puts mod2.method(:foo).inspect
=end

[yugui (Yuki Sonoda)]

• Due date set to 12/24/2008
• Category changed from core to YARV

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=end

[yugui (Yuki Sonoda)]

• Status changed from Open to Closed

=begin
fixed
=end