Improved fix

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/codegen/OperandStack.java

@@ -31,18 +31,21 @@ enum OperandCategory {
 
 	private Stack<TypeBinding> stack;
 	private ClassFile classFile;
+	private Scope scope;
 
 	public OperandStack() {}
 
 	public OperandStack(ClassFile classFile) {
 		this.stack = new Stack<>();
 		this.classFile = classFile;
+		this.scope = classFile.referenceBinding.scope;
 	}
 
 	@SuppressWarnings("unchecked")
 	private OperandStack(OperandStack operandStack) {
 		this.stack = (Stack<TypeBinding>) operandStack.stack.clone();
 		this.classFile = operandStack.classFile;
+		this.scope = operandStack.scope;
 	}
 
 	protected OperandStack copy() {
@@ -53,9 +56,6 @@ public void push(TypeBinding typeBinding) {
 		if (typeBinding == null) {
 			throw new AssertionError("Attempt to push null on operand stack!"); //$NON-NLS-1$
 		}
-		if (typeBinding instanceof ArrayBinding array && !array.leafComponentType.isReifiable()) {
-			typeBinding = this.classFile.referenceBinding.scope.createArrayType(erasure(array.leafComponentType), array.dimensions);
-		}
 		/* 4.9.2 Structural Constraints: ...
 		   An instruction operating on values of type int is also permitted to operate on
 		   values of type boolean, byte, char, and short.
@@ -64,12 +64,17 @@ public void push(TypeBinding typeBinding) {
 		*/
 		this.stack.push(switch(typeBinding.id) {
 			case TypeIds.T_boolean, TypeIds.T_byte, TypeIds.T_short, TypeIds.T_char -> TypeBinding.INT;
-			default -> typeBinding.erasure();
+			default -> erasure(typeBinding);
 		});
 	}
 
-	private TypeBinding erasure(TypeBinding leafComponentType) {
-		return this.classFile.referenceBinding.scope.getJavaLangObject(); // FIXME: coarse...
+	private TypeBinding erasure(TypeBinding type) {
+		if (type instanceof ArrayBinding array) {
+			TypeBinding leafComponentType = erasure(array.leafComponentType);
+			return leafComponentType == array.leafComponentType ? type : this.scope.createArrayType(leafComponentType, array.dimensions); //$IDENTITY-COMPARISON$
+		}
+		TypeBinding erasure = type.erasure();
+		return erasure.isReifiable() ? erasure : this.scope.getJavaLangObject(); // workaround for IntersectionTypeBinding18.erasure() returning receiver.
 	}
 
 	public void push(int localSlot) {
@@ -81,8 +86,7 @@ public void push(int localSlot) {
 	}
 
 	public void push(char[] typeName) {
-		Scope scope = this.classFile.referenceBinding.scope;
-		Supplier<ReferenceBinding> finder = scope.getCommonReferenceBinding(typeName);
+		Supplier<ReferenceBinding> finder = this.scope.getCommonReferenceBinding(typeName);
 		TypeBinding type = finder != null ? finder.get() : TypeBinding.NULL;
 		push(type);
 	}