Bug #8133: Regexp macro %r{} is loosing backslash on "\}"

• Status: Closed
• Assignee: -
• Target version: 2.1.0
• ruby -v: 2.0.0

[jstribny (Josef Stribny)]

Hello,

Ruby 2.0.0 is loosing the backslash when used on "}" string (exact match).

How to reproduce in irb:

2.0.0-p0 :003 > %r{}}
=> /}/
2.0.0-p0 :004 > %r{{}
=> /{/

Compared to:

1.9.3p392 :001 > %r{{}
=> /{/
1.9.3p392 :002 > %r{}}
=> /}/

This shouldn't probably happen.

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Rejected

There is nothing different, as '}' is not a regexp meta character.

[vo.x (Vit Ondruch)]

• Status changed from Rejected to Open

It doesn't look to be issue of regexp but issue of parser:

C:\Projects>irb
irb(main):001:0> a = %r|}|
=> /}/
irb(main):002:0> b = %r{}}
=> /}/
irb(main):003:0> a == b
=> false

a and b are apparently not the same. They used to be the same in Ruby 1.9.3.

[nobu (Nobuyoshi Nakada)]

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

This issue was solved with changeset r39858.
Josef, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

parse.y: escape all closing parens

• parse.y (simple_re_meta): escape all closing characters, not only
  round parenthesis. [ruby-core:53578] [Bug #8133]

[vo.x (Vit Ondruch)]

nobu (Nobuyoshi Nakada) wrote:

This issue was solved with changeset r39858.

Thank you.

[mame (Yusuke Endoh)]

Just for information: r39858 introduces the behavior change.
Whether %r{n{3}}} matches with:

      | "nnn}" | "n{3}}"

----------+--------+---------
1.9.3p392 | YES | NO
2.0.0p0 | NO | YES
trunk | YES | NO

--
Yusuke Endoh [e-mail]

[nagachika (Tomoyuki Chikanaga)]

Hmm, is it a bug introduced in 2.0.0?
I personally feel the behavior of 2.0.0 is natural.

[naruse (Yui NARUSE)]

nagachika (Tomoyuki Chikanaga) wrote:

Hmm, is it a bug introduced in 2.0.0?
I personally feel the behavior of 2.0.0 is natural.

} in this case doesn't escape a regexp meta character, it escapes closing terminator of %r{...} literal.

[nagachika (Tomoyuki Chikanaga)]

mame (Yusuke Endoh) wrote:

Just for information: r39858 introduces the behavior change.
Whether %r{n{3}}} matches with:

      | "nnn}" | "n{3}}"

----------+--------+---------
1.9.3p392 | YES | NO
2.0.0p0 | NO | YES
trunk | YES | NO

On my environment the result was exactly opposite.

$ cat regexp_test.rb
re = %r{n{3}}}
p re
p [re =~ "nnn}", re =~ "n{3}}"]

ruby 1.9.3dev (2011-09-24 revision 33322) [x86_64-darwin10.8.0]
/n{3}}/
[nil, 0]

ruby 2.0.0p96 (2013-03-25 revision 39918) [x86_64-darwin10.8.0]
/n{3}}/
[0, nil]

ruby 2.1.0dev (2013-03-24 trunk 39908) [x86_64-darwin10.8.0]
/n{3}}/
[nil, 0]

[nagachika (Tomoyuki Chikanaga)]

naruse (Yui NARUSE) wrote:

} in this case doesn't escape a regexp meta character, it escapes closing terminator of %r{...} literal.

I agree. It's reasonable.
Thanks.