Array.Append mutates first argument when result is small

[zynque]

Array.Append should not alter the two arrays passed to this function, however, when the resulting array is 32 elements or less, the array value passed as the first argument gets mutated.

Elm.Core version: 5.0.0
Browser/OS: Chrome 55.0.2883.87 m / Windows 10

Example of this behavior:

a1 = Array.repeat 20 1 
a2 = Array.repeat 12 2
a3 = Array.append a1 a2

-- a1: Array.fromList [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2]
-- a2: Array.fromList [2,2,2,2,2,2,2,2,2,2,2,2]
-- a3: Array.fromList [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2]

a4 = Array.repeat 20 1
a5 = Array.repeat 13 2
a6 = Array.append a4 a5

-- a4: Array.fromList [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1]
-- a5: Array.fromList [2,2,2,2,2,2,2,2,2,2,2,2,2]
-- a6: Array.fromList [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2]

[process-bot]

Thanks for the issue! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[process-bot]

Thanks for the issue! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[jvoigtlaender]

Duplicate, covered in https://github.com/elm-lang/core/issues/649, isn't it?

[jvoigtlaender]

Duplicate, covered in https://github.com/elm-lang/core/issues/649, isn't it?

[zynque]

Apologies for the oversight. Thanks for closing!

[zynque]

Apologies for the oversight. Thanks for closing!