Bug #1901: Segfault for Enumerable#count When Aliased to #size

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 1.9.2dev (2009-08-05 trunk 24397) [i686-linux]

[runpaint (Run Paint Run Run)]

=begin
$ cat /tmp/enum-size.rb
class E
include Enumerable
alias :size :count
def each
yield 1
end
end

p E.new.count

$ ruby -v /tmp/enum-size.rb
ruby 1.9.2dev (2009-08-05 trunk 24397) [i686-linux]
Segmentation fault

1.8.7 gives a SystemStackError. It would be nice if #count recognized #size was an alias and didn't try to invoke it.
=end

[runpaint (Run Paint Run Run)]

• File enumerable-alias enumerable-alias added

=begin
This still occurs on trunk. May I suggest it block 1.9.2? (The, rather impressive, stack trace is attached).
=end

[matz (Yukihiro Matsumoto)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

=begin
This issue was solved with changeset r25560.
Run Paint, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

=end

[matz (Yukihiro Matsumoto)]

=begin
Hi,

In message "Re: [ruby-core:24794] [Bug #1901] Segfault for Enumerable#count When Aliased to #size"
on Thu, 6 Aug 2009 23:24:18 +0900, Run Paint Run Run [e-mail] writes:

| class E
| include Enumerable
| alias :size :count
| def each
| yield 1
| end
| end
|
| p E.new.count
|
| $ ruby -v /tmp/enum-size.rb
| ruby 1.9.2dev (2009-08-05 trunk 24397) [i686-linux]
| Segmentation fault
|
|1.8.7 gives a SystemStackError. It would be nice if #count recognized #size was an alias and didn't try to invoke it.

I fixed this by r25560, but I still consider the fix is implementation
dependent, so that some implementation might (and can) cause infinite
recursion.

						matz.

=end

[nobu (Nobuyoshi Nakada)]

=begin
Hi,

At Fri, 30 Oct 2009 08:09:02 +0900,
Yukihiro Matsumoto wrote in [ruby-core:26420]:

I fixed this by r25560, but I still consider the fix is implementation
dependent, so that some implementation might (and can) cause infinite
recursion.

Though I've missed the original report, it feels like there is
another bug that couldn't catch the stack overflow properly.

--
Nobu Nakada

=end