Calling isdefined with integer argument results in failed assertion or wrong result

[simonster]

On a release build (commit 7287321), isdefined with a field index returns the correct result if called from the REPL, but an incorrect result if called within a function:

julia> mutable struct MyStruct
           len::Int
           data::Array{Float64}
           MyStruct(len::Int) = new(len)
           MyStruct(len::Int, data::Array{Float64}) = new(len, data)
       end

julia> ms = MyStruct(2, [3.2, -1.7])
MyStruct(2, [3.2, -1.7])

julia> isdefined(ms, 2)
true

julia> f(x) = isdefined(x, 2)
f (generic function with 1 method)

julia> f(ms)
false

On a debug build, Julia crashes at the last line with:

Assertion failed: (jl_is_primitivetype(jl_typeof(v))), function jl_unbox_int64, file /usr/local/julia/src/datatype.c, line 541.

signal (6): Abort trap: 6
while loading no file, in expression starting on line 0
__pthread_kill at /usr/lib/system/libsystem_kernel.dylib (unknown line)
Allocations: 3096855 (Pool: 3096325; Big: 530); GC: 6
fish: '/usr/local/julia/julia' terminated by signal SIGABRT (Abort)

This is a relatively recent issue that is only present on master. #22769 seems like a possible culprit, but I haven't bisected.

[yuyichao]

No it's from #22818 ...