Backport #8210: Multibyte character interfering with end-line character within a regex

• Status: Closed
• Assignee: usa (Usaku NAKAMURA)

[sawa (Tsuyoshi Sawada)]

=begin
With this regex:

regex1 = /\z/

the following strings match as expected:

"hello" =~ regex1 # => 5
"こんにちは" =~ regex1 # => 5

but with these regexes:

regex2 = /#$/?\z/
regex3 = /\n?\z/

they show difference:

"hello" =~ regex2 # => 5
"hello" =~ regex3 # => 5
"こんにちは" =~ regex2 # => nil
"こんにちは" =~ regex3 # => nil

The string encoding is UTF-8, and the OS is Linux (i.e., $/ is "\n"). I expect them to behave the same, and believe this is a bug.
=end

[sawa (Tsuyoshi Sawada)]

=begin
A different regex:

regex4 = /[[:space:]]?\z/

seems to work as expected:

"hello" =~ regex4 # => 5
"こんにちは" =~ regex4 # => 5

=end

[sawa (Tsuyoshi Sawada)]

=begin
Still a different regex:

regex5 = /\n?$/

seems to work as expected:

"hello" =~ regex5 # => 5
"こんにちは" =~ regex5 # => 5

=end

[sawa (Tsuyoshi Sawada)]

=begin
The problem seems to happen with combination of a certain token, ?, and \z.

"こんにちは" =~ /a?\z/ # => nil
"こんにちは" =~ / ?\z/ # => nil
"こんにちは" =~ /\t?\z/ # => nil
"こんにちは" =~ /\n?\z/ # => nil
"こんにちは" =~ /\s?\z/ # => nil
"こんにちは" =~ /.?\z/ # => 4
"こんにちは" =~ /\S?\z/ # => 4
"こんにちは" =~ /\W?\z/ # => 5
"こんにちは" =~ /あ?\z/ # => 5
"こんにちは" =~ /\w?\z/ # => 5

=end

[sawa (Tsuyoshi Sawada)]

Is this bug report wrong? If so, please note so.

[naruse (Yui NARUSE)]

• Category set to M17N
• Status changed from Open to Assigned
• Assignee set to naruse (Yui NARUSE)
• Target version set to 2.1.0

sawa (Tsuyoshi Sawada) wrote:

Is this bug report wrong? If so, please note so.

This looks really bug of oniguruma/onigmo.

[acheong87 (Andrew Cheong)]

Contributing notes regarding this bug can be found here: http://stackoverflow.com/a/15885857/925913.

[rondinif (Franco Rondini)]

Just edited the answer and test code available

[k_takata (Ken Takata)]

• File fix-8210-1.diff fix-8210-1.diff added
• File fix-8210-2.diff fix-8210-2.diff added

This problem was caused by optimization of \z.
I wrote two patches to fix this problem.

Maybe fix-8210-1.diff is more efficient than fix-8210-2.diff,
but the former one tries to do backward search when 'start==range'
after 'start' is adjusted. This behavior is a little bit confusing.

[sawa (Tsuyoshi Sawada)]

Is either of k_takata's bug fix going to be incorporated?

[naruse (Yui NARUSE)]

k_takata (Ken Takata) wrote:

This problem was caused by optimization of \z.
I wrote two patches to fix this problem.

Maybe fix-8210-1.diff is more efficient than fix-8210-2.diff,
but the former one tries to do backward search when 'start==range'
after 'start' is adjusted. This behavior is a little bit confusing.

k_takata (Ken Takata) wrote:

This problem was caused by optimization of \z.
I wrote two patches to fix this problem.

Maybe fix-8210-1.diff is more efficient than fix-8210-2.diff,
but the former one tries to do backward search when 'start==range'
after 'start' is adjusted. This behavior is a little bit confusing.

I think -1 is suitable because it looks to keep original intention more than -2.

[k_takata (Ken Takata)]

• File fix-8210-1-update.diff fix-8210-1-update.diff added

I think -1 is suitable because it looks to keep original intention more than -2.

Thanks for your comment.
I have updated onigmo's tmp/ruby-2.0.x branch.
https://github.com/k-takata/Onigmo/tree/f22cf2e566712cace60d17f84d63119d7c5764ee

I also attach an updated patch so that can be applied to Ruby 1.9.3.

[naruse (Yui NARUSE)]

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

This issue was solved with changeset r40276.
Tsuyoshi, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• Merge Onigmo 5.13.4 f22cf2e566712cace60d17f84d63119d7c5764ee.
  [bug] fix problem with optimization of \z (Issue #16) [Bug #8210]

[naruse (Yui NARUSE)]

• Tracker changed from Bug to Backport
• Project changed from Ruby master to Backport200
• Category deleted (M17N)
• Status changed from Closed to Assigned
• Assignee changed from naruse (Yui NARUSE) to nagachika (Tomoyuki Chikanaga)
• Target version deleted (2.1.0)

[k_takata (Ken Takata)]

I think it's better to backport this patch to Ruby 1.9.3 too.

[nagachika (Tomoyuki Chikanaga)]

• Status changed from Assigned to Closed

This issue was solved with changeset r40384.
Tsuyoshi, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

merge revision(s) 40276: [Backport #8210]

* Merge Onigmo 5.13.4 f22cf2e566712cace60d17f84d63119d7c5764ee.
  [bug] fix problem with optimization of \z (Issue #16) [Bug #8210]

[nagachika (Tomoyuki Chikanaga)]

• Project changed from Backport200 to Backport193
• Status changed from Closed to Assigned
• Assignee changed from nagachika (Tomoyuki Chikanaga) to usa (Usaku NAKAMURA)

Move to Backport93.
But Onigmo is merged after 2.0. I didn't confirm this patch can merge to ruby_1_9_3...

[usa (Usaku NAKAMURA)]

• Status changed from Assigned to Closed

This issue was solved with changeset r40713.
Tsuyoshi, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• regexec.c (onig_search): fix problem with optimization of \z.
  [Backport #8210]
  patched by k_tanaka at [ruby-core:54251].

[k_takata (Ken Takata)]

Hi usa,

• regexec.c (onig_search): fix problem with optimization of \z.
  [Backport #8210]
  patched by k_tanaka at [ruby-core:54251].

Thank you for merging my patch.
BTW, my name is not tanaka...