Bug #12002: **param notation seems to be creating a new hash in ruby 2.2.0

• Status: Rejected
• Assignee: -
• Target version: -
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN

[chucke (Tiago Cardoso)]

I found the regression regarding the handling of the ** notation for options hash in a method. In ruby 2.1 and lower, it seems to always be handled in the same way, i.e. it is always the same object:

def hashie1(o={})
  puts o.object_id
end
def hashie2(**o)
  puts o.object_id
end

v={}
puts v.object_id
hashie1(v)
hashie2(v)

# 2.0.0
69830362391800
69830362391800
69830362391800

# 2.1.6 
69884363736320
69884363736320
69884363736320

# 2.2.4
69922787909840
69922787909840
69922787909700

# 2.3.0
69915134419200
69915134419200
69915134419000

I didn't find any documentation regarding this change. Is it supposed to work the way it works in 2.2 and 2.3? Because my understanding was that ** was supposed to be the new notation and should just work as the previous notation.

[wanabe (_ wanabe)]

r48239 did, according to git bisect.

[wanabe (_ wanabe)]

• Related to Feature #10440: Optimize keyword and splat argument added

[nobu (Nobuyoshi Nakada)]

• Description updated (diff)
• Status changed from Open to Rejected

It is not a bug.
As *rest, modifying o should not affect the object in the caller scope.