Array return value is broken when returning null

[alexvas]

Commands

java -version -Aversion -AprintGitProperties -verbose -AprintVerboseGenerics
java -jar "$CHECKER_FRAMEWORK/checker/dist/checker.jar" -processor nullness Foo.java

Inputs

A single input named Foo.java:

import org.checkerframework.checker.nullness.qual.Nullable;

interface Foo {
}

interface Bar {

	default @Nullable Foo[] bazz() {
		return null;
	}
}

Outputs

openjdk version "17.0.11" 2024-04-16
OpenJDK Runtime Environment (build 17.0.11+9-Ubuntu-122.04.1)
OpenJDK 64-Bit Server VM (build 17.0.11+9-Ubuntu-122.04.1, mixed mode, sharing)
Foo.java:9: error: [return] incompatible types in return.
                return null;
                       ^
  type of expression: null (NullType)
  method return type: @Initialized @Nullable Foo @Initialized @NonNull []
1 error

Expectation

The case is valid. No error should be issued.

[msridhar]

I think you need to write Foo @Nullable [] since it's a type use annotation. @Nullable Foo [] means the pointers inside the array to the Foo objects may be null.

[alexvas]

@msridhar, Thank you. My bad.