Accessing the structure field in the slice fails with panic #1553

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opened 2025-12-28 17:16:49 +00:00 by sami · 0 comments

sami commented

2025-12-28 17:16:49 +00:00

Owner

Originally created by @Turalchik on GitHub (Sep 16, 2025).

func TestBla(t *testing.T) {
	src := `package main
    type nested struct{ t int }
	type test struct{ a []nested }
	
	func Main() int {
		var myStruct = test{a: make([]nested, 1)}
		return myStruct.a[0].t
	}`
	eval(t, src, big.NewInt(1))
}

Current Behavior

Test returns an error: at instruction 15 (PICKITEM): invalid conversion: Null/ByteString.

Expected Behavior

Test should return 1.

Possible Solution

I think make() should fill the array not with stackitem.Null{}, but with zero values for each type.

Steps to Reproduce

Run the test above.

Your Environment

v0.112.0

Originally created by @Turalchik on GitHub (Sep 16, 2025).  ```golang func TestBla(t *testing.T) { src := `package main type nested struct{ t int } type test struct{ a []nested } func Main() int { var myStruct = test{a: make([]nested, 1)} return myStruct.a[0].t }` eval(t, src, big.NewInt(1)) } ``` ## Current Behavior Test returns an error: `at instruction 15 (PICKITEM): invalid conversion: Null/ByteString`. ## Expected Behavior Test should return 1. ## Possible Solution I think `make()` should fill the array not with `stackitem.Null{}`, but with zero values for each type. ## Steps to Reproduce  Run the test above. ## Your Environment  v0.112.0