A DESCRIPTION OF THE PROBLEM :
If a text file is UTF-8 and has an odd number of characters, trying to read it as UTF-16 throws an Error caused by MalformedInputException:

Files.readString(Paths.get("text.txt"), StandardCharsets.UTF_16);

A comment in the java.lang.String method which causes the Error says "// Substitution is always enabled, // so this shouldn't happen". Clearly the intent is that only the MalformedInputException should be thrown.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Create a UTF-8 file text.txt containing an odd number of characters. Create, compile and run Test.java with the provided source code.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Exception caught, no output.
ACTUAL -
Exception in thread "main" java.lang.Error: java.nio.charset.MalformedInputException: Input length = 1
        at java.base/java.lang.String.decodeWithDecoder(String.java:1220)
        at java.base/java.lang.String.newStringNoRepl1(String.java:796)
        at java.base/java.lang.String.newStringNoRepl(String.java:748)
        at java.base/java.lang.System$2.newStringNoRepl(System.java:2439)
        at java.base/java.nio.file.Files.readString(Files.java:3370)
        at Test.main(Test.java:8)
Caused by: java.nio.charset.MalformedInputException: Input length = 1
        at java.base/java.nio.charset.CoderResult.throwException(CoderResult.java:274)
        at java.base/java.lang.String.decodeWithDecoder(String.java:1213)
        ... 5 more

---------- BEGIN SOURCE ----------
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;

public class Test {
    public static void main(String[] args) {
        try {
            Files.readString(Paths.get("text.txt"), StandardCharsets.UTF_16);
        } catch (Exception e) {}
    }
}
---------- END SOURCE ----------

FREQUENCY : always