Bug #20094: Inline while loop behavior changed unexpectedly in 3.3.0

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: 3.3.1
• Backport: 3.0: UNKNOWN, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONE

[sisyphus_cg (Sisyphus CG)]

The behavior of the inline while loop has changed in 3.3.0. This unexpectedly broke my code and I couldn't find anything in the changelog about it so reporting it as a bug.

In ruby <= 3.2:

(p 1) while false      # nothing
(p 1; p 2) while false # nothing

In ruby 3.3:

(p 1) while false      # 1
(p 1; p 2) while false # 1 2

Essentially, if the left hand side looks like a statement, now it is treated as a do-while loop. In ruby 3.2 and less this only happened with explicit use of begin and end.

[nobu (Nobuyoshi Nakada)]

https://github.com/ruby/ruby/pull/9373

[jeremyevans0 (Jeremy Evans)]

• Status changed from Open to Closed

Fixed by bc002971b6ad483dbf69b8a275c44412bb6ab954

[jeremyevans0 (Jeremy Evans)]

• Backport changed from 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN to 3.0: UNKNOWN, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: REQUIRED

[naruse (Yui NARUSE)]

• Backport changed from 3.0: UNKNOWN, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: REQUIRED to 3.0: UNKNOWN, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONE

ruby_3_3 119d447d42d4645ac919ee53f3ec294deaa7c59b merged revision(s) bc002971b6ad483dbf69b8a275c44412bb6ab954.

[rbjl (Jan Lelis)]

It seems like the bug is still present in Ruby 3.3.1:

(p 1) while false # 1

[Eregon (Benoit Daloze)]

Indeed:

$ ruby -ve '(p 1) while false'
ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x86_64-linux]
$ ruby -ve '(p 1) while false'
ruby 3.3.1 (2024-04-23 revision c56cd86388) [x86_64-linux]
1

[nevans (Nicholas Evans)]

Can we reopen this bug (please), or should we create a new issue?

[nagachika (Tomoyuki Chikanaga)]

• ruby -v changed from 3.3.0 to 3.3.1
• Backport changed from 3.0: UNKNOWN, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONE to 3.0: UNKNOWN, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: REQUIRED

I see the issue was fixed on master branch.
I will revert back Backport field to "3.3: REQUIRED", but stay the ticket status "Closed.

[nagachika (Tomoyuki Chikanaga)]

I have found that the backport commit was reverted at https://github.com/ruby/ruby/commit/9f18cbd7964f32f224e7d0efba79ee0476a442e0.

[k0kubun (Takashi Kokubun)]

• Backport changed from 3.0: UNKNOWN, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: REQUIRED to 3.0: UNKNOWN, 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONE

ruby_3_3 0044b6aefc656874adb9266829f19870dcd3d75e merged revision(s) bc002971b6ad483dbf69b8a275c44412bb6ab954.

[k0kubun (Takashi Kokubun)]

It was previously reverted presumably because the cherry-pick of bc002971b6ad483dbf69b8a275c44412bb6ab954 to ruby_3_3 doesn't really work. I had to manually create a whole backport patch without relying on git for that reason. I encourage people to file a backport pull request to ruby_3_3 (and make the CI green, which was the hard thing for this ticket) if you want to see a change backported to stable branches.

[k0kubun (Takashi Kokubun)]

It seems like the bug is still present in Ruby 3.3.1

Ruby 3.3.2 has been released today. It shouldn't have this issue.