Bug #15052: must not optimize `foo(**{})` out

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN

[mame (Yusuke Endoh)]

A keyword rest argument with empty hash, **{}, is removed during parsing phase. However, under the current spec of keyword parameters, this leads to a problem:

def foo(opt = "opt", **hsh)
  p [opt, hsh]
end

foo({}, **{})  #=> expected: [{}, {}], actual: ["opt", {}]

foo({}, **{}) is obviously expected to pass the first {} to opt, and the second **{} to **hsh. However, **{} is removed at parsing phase, sp the first {} is considered as a keyword rest argument, which causes the above strange result.

So, we cannot optimize **{} out, unless keyword argument is separated from normal arguments #14183. (The current spec is really intractable not only for Ruby users but also for Ruby developers!)

[mame (Yusuke Endoh)]

• Related to Bug #15078: Hash splat of empty hash should not create a positional argument. added

[mame (Yusuke Endoh)]

• Related to Bug #15087: Segmentation fault with splat and block added

[jeremyevans0 (Jeremy Evans)]

• Status changed from Open to Closed

Fixed by 1d5066efb08cbb328ba528a5f8be1708584b659f.