Bug #14373: Methods with more than 32 keyword arguments with default values have some of the arguments set to default despite being passed in.

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.5.0p0 (2017-12-25 revision 61468) [x86_64-linux], ruby 2.4.0p0 (2016-12-24 revision 57164) [x86_64-linux]
• Backport: 2.3: REQUIRED, 2.4: REQUIRED, 2.5: REQUIRED

[sk (SK Liew)]

class Test
  #  33 keyword arguments
  def test1(a0: '', a1: '', a2: '', a3: '', a4: '', a5: '', a6: '', a7: '', a8: '', b0: '', b1: '', b2: '', b3: '', b4: '', b5: '', b6: '', b7: '', b8: '', c0: '', c1: '', c2: '', c3: '', c4: '', c5: '', c6: '', c7: '', c8: '', d0: '', d1: '', d2: '', d3: '', d4: '', d5: '')
    puts a1
    puts d5
    puts '-------'
  end
  #  32 keyword arguments
  def test2(a0: '', a1: '', a2: '', a3: '', a4: '', a5: '', a6: '', a7: '', a8: '', b0: '', b1: '', b2: '', b3: '', b4: '', b5: '', b6: '', b7: '', b8: '', c0: '', c1: '', c2: '', c3: '', c4: '', c5: '', c6: '', c7: '', c8: '', d0: '', d1: '', d2: '', d3: '', d4: '')
    puts a1
    puts d4
    puts '-------'
  end
end
puts 'Test1 with a1, expects a1, prints nothing in 2.5, prints a1 in 2.4 and 2.3'
Test.new.test1(a1: 'a1')

puts 'Test1 with a1 and d5, expects a1 and d5 but only prints a1'
Test.new.test1(a1: 'a1', d5: 'd5')

puts 'Test1 with d5, expects d5 but prints nothing'
Test.new.test1({d5: 'd5'})

puts 'Test2 with a1 and d4, as expected'
Test.new.test2(a1: 'a1', d4: 'd4')

puts 'Test2 with a1, as expected'
Test.new.test2(a1: 'a1')

The code above describes the issues. I noticed that Ruby 2.5 behaves slightly differently from 2.3 and 2.4 (as described in the first test case).

[shevegen (Robert A. Heiler)]

I ran the code and indeed, this is very strange behaviour.

The bigget surprise to me was the "prints nothing in 2.5, prints
a1 in 2.4 and 2.3" part. I know way too little to say anything
but to me this looks like a bug/regression.

I guess your code example could be used for new tests to ensure
that the functionality does not disappear in new ruby releases,
if it is a bug that is. :) (I just can't think of a reason why
it would work on ruby 2.4 but not 2.5)

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset trunk|r61940.

---

vm_insnhelper.c: fix many keyword arguments

• vm_insnhelper.c (vm_check_keyword): if the index exceeds the
  width of unspecified bits, that argument is specified.
  unspecified_bits still be a fixnum if the actual arguments do
  not exceed the limit, regardless the formal parameters size.
  [ruby-core:84921] [Bug #14373]

[nobu (Nobuyoshi Nakada)]

• Has duplicate Bug #15731: Wrong evaluation of many keyword default arguments in 2.3 - 2.5 added

[nobu (Nobuyoshi Nakada)]

• Backport changed from 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN to 2.3: REQUIRED, 2.4: REQUIRED, 2.5: REQUIRED

[greneholt (Connor McKay)]

I recently confirmed this bug still exists on the most recent 2.5 release, 2.5.8. Was this fix ever backported to the 2.5 branch?