Bug #7870

Time.now == "" causes an infinite loop

Added by Eric Hodel about 1 year ago. Updated about 1 year ago.

[ruby-core:52305]
Status:Closed
Priority:Urgent
Assignee:Nobuyoshi Nakada
Category:core
Target version:2.0.0
ruby -v:ruby 2.0.0dev (2013-02-08) [x86_64-darwin12.2.1] Backport:

Description

=begin
This is a regression from 1.9.

2.0.0 branch:

$ ./ruby20 -v ../branches/ruby200/test.rb
ruby 2.0.0dev (2013-02-08) [x86
64-darwin12.2.1]
../branches/ruby200/test.rb:1: warning: possibly useless use of == in void context
../branches/ruby
200/test.rb:1: stack level too deep (SystemStackError)

1.9:

$ ruby19 -v test.rb
ruby 1.9.3p374 (2013-01-15 revision 38858) [x86_64-darwin12.2.1]
test.rb:1: warning: possibly useless use of == in void context

This also reproduces in trunk.

=end


Related issues

Related to Backport200 - Backport #7875: Backport r39292 to 2.0.0 which fixes #7870 Closed 02/18/2013

Associated revisions

Revision 39292
Added by Nobuyoshi Nakada about 1 year ago

compar.c: inversed comarison without infinite recursion

  • compar.c (rb_invcmp): compare by inversed comarison, with preventing from infinite recursion. [Bug #7870]
  • string.c (rbstrcmpm), time.c (timecmp): get rid of infinite recursion.

History

#1 Updated by Eric Hodel about 1 year ago

  • Assignee set to Nobuyoshi Nakada

r38044 is the culprit.

Previously Ruby would return nil if the other object did not have to_str, now ruby calls other <=> self when other is not a String and does not have <=> leading to the infinite loop.

#2 Updated by Yusuke Endoh about 1 year ago

  • Priority changed from Urgent to Normal

I don't think that this is a showstopper, unless there is many or famous application depending on this behavior. Do you know anything?

After it is fixed in trunk, we may backport the patch to 2.0.0, but don't necessarily have to do so. I guess that it can be fixed 2.0.0-pXXX later (depending on Nagachika-san).

Yusuke Endoh mame@tsg.ne.jp

#3 Updated by Eric Hodel about 1 year ago

Fog breaks due to this change (it is how I discovered it):

https://github.com/fog/fog/blob/master/lib/fog/core/attributes.rb#L53-L62

This compares a Time with the empty string leading to the infinite loop.

Fog provides an API for cloud services such as Amazon AWS, OpenStack, etc. It is fairly popular.

#4 Updated by Koichi Sasada about 1 year ago

  • Priority changed from Normal to Urgent

#5 Updated by Yusuke Endoh about 1 year ago

  • Status changed from Open to Assigned

drbrain, thank you! That is terrible.

Nobu, please check and fix it!

Yusuke Endoh mame@tsg.ne.jp

#6 Updated by Nobuyoshi Nakada about 1 year ago

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

This issue was solved with changeset r39292.
Eric, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.


compar.c: inversed comarison without infinite recursion

  • compar.c (rb_invcmp): compare by inversed comarison, with preventing from infinite recursion. [Bug #7870]
  • string.c (rbstrcmpm), time.c (timecmp): get rid of infinite recursion.

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