Bug #9202: Array#uniq freezes duplicate strings

• Status: Closed
• Assignee: Glass_saga (Masaki Matsushita)
• Target version: 2.1.0
• ruby -v: ruby 2.1.0dev (2013-12-02 trunk 43958) [x86_64-darwin13.0]
• Backport: 1.9.3: DONTNEED, 2.0.0: DONTNEED

[drbrain (Eric Hodel)]

I imagine this is related to the recent frozen string changes. This behavior change in Array#uniq breaks RubyGems:

$ cat test.rb
p unique: %w[a].uniq.any? { |item| item.frozen? }
p duplicate: %w[a a].uniq.any? { |item| item.frozen? }
$ ruby -v test.rb
ruby 2.0.0p247 (2013-06-27 revision 41674) [x86_64-darwin12.4.0]
{:unique=>false}
{:duplicate=>false}
$ make runruby
./miniruby -I../trunk/lib -I. -I.ext/common ../trunk/tool/runruby.rb --extout=.ext -- --disable-gems ../trunk/test.rb
{:unique=>false}
{:duplicate=>true}

[drbrain (Eric Hodel)]

• ruby -v changed from ruby 2.0.0dev (2012-11-29 trunk 37968) [x86_64-darwin12.2.0] to ruby 2.1.0dev (2013-12-02 trunk 43958) [x86_64-darwin13.0]

[normalperson (Eric Wong)]

It's not r43870 (Use rb_fstring() to de-duplicate hash string keys)
Bisecting now...

[normalperson (Eric Wong)]

bisected to r43194:

 * array.c (rb_ary_uniq): use rb_hash_keys().

 * internal.h: define rb_hash_keys() as internal API.

 * hash.c (rb_hash_keys): ditto.

[normalperson (Eric Wong)]

• File 0001-Array-uniq-uniq-does-not-return-frozen-hash-keys.patch 0001-Array-uniq-uniq-does-not-return-frozen-hash-keys.patch added

This should fix it, can you confirm/? Thanks

[Glass_saga (Masaki Matsushita)]

• Assignee changed from Anonymous to Glass_saga (Masaki Matsushita)

I confirmed it. Thank you for your patch!

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

This issue was solved with changeset r43969.
Eric, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• array.c (ary_add_hash): set and return values because string keys
  will be frozen. [ruby-core:58809] [Bug #9202]

• array.c (rb_ary_uniq_bang): ditto.

• array.c (rb_ary_or): ditto.

• array.c (rb_ary_uniq): ditto.

• test/ruby/test_array.rb: tests for above.

The patch is from normalperson (Eric Wong).

[normalperson (Eric Wong)]

"Glass_saga (Masaki Matsushita)" [e-mail] wrote:

I confirmed it. Thank you for your patch!

No problem, thanks for the review.

Also, I think we may remove rb_hash_keys from internal.h and make it
static again.