Incorrect behaviour of strings.substring_from according to documentation

[AntonGorov195]

Context

Odin: dev-2025-08:fb4641307
OS: Linux Mint 22.1, Linux 6.8.0-90-generic
CPU: Intel(R) Core(TM) i5-9400F CPU @ 2.90GHz
RAM: 15929 MiB
Backend: LLVM 20.1.8

According to substring_from documentation at core:strings line 3448 (3444 on my Odin version)

Think of it as slicing s[rune_start:] but rune-wise.

This is false.

package substring

import "core:strings"

main :: proc() {
    assert("a"[1:] == "", "string slicing failed") // empty string
    _, ok := strings.substring_from("a", 1)
    assert(ok, "substring_from failed")
}

Expected Behavior

runtime assertion: string slicing failed or

Current Behavior

runtime assertion: substring_from failed

Steps to Reproduce

Run the above code with odin run .