another test to challenge nested generics with raw type within

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/CastTest.java

@@ -3725,6 +3725,58 @@ The method bar() is undefined for the type Object
 	runner.runNegativeTest();
 }
 
+public void testGH2470_generic2() {
+	if (this.complianceLevel < ClassFileConstants.JDK1_8) return;
+	Runner runner = new Runner();
+	runner.customOptions = getCompilerOptions();
+	runner.customOptions.put(CompilerOptions.OPTION_ReportUnnecessaryTypeCheck, CompilerOptions.ERROR);
+	runner.testFiles = new String[] {
+		"X.java",
+		"""
+		import java.util.List;
+		import java.util.function.Supplier;
+		interface XListSupplier extends Supplier<List<X>> {}
+		interface XList extends List<X> {}
+		public class X {
+			void bar() {}
+			@SuppressWarnings({"unchecked"})
+			void test0(Supplier<List> sup) {
+				((Supplier<List<X>>) sup).get().get(0).bar();
+			}
+			@SuppressWarnings({"unchecked"})
+			void test1(Supplier<List> sup) {
+				((XListSupplier) sup).get().get(0).bar();
+			}
+			@SuppressWarnings({"unchecked"})
+			void test2(List list) {
+				((XList) list).get(0).bar();
+				list.get(0).bar();
+			}
+		}
+		"""
+	};
+	runner.expectedCompilerLog =
+			"""
+				----------
+				1. ERROR in X.java (at line 9)
+					((Supplier<List<X>>) sup).get().get(0).bar();
+					^^^^^^^^^^^^^^^^^^^^^^^^^
+				Cannot cast from Supplier<List> to Supplier<List<X>>
+				----------
+				2. ERROR in X.java (at line 13)
+					((XListSupplier) sup).get().get(0).bar();
+					^^^^^^^^^^^^^^^^^^^^^
+				Cannot cast from Supplier<List> to XListSupplier
+				----------
+				3. ERROR in X.java (at line 18)
+					list.get(0).bar();
+					            ^^^
+				The method bar() is undefined for the type Object
+				----------
+				""";
+	runner.runNegativeTest();
+}
+
 public static Class testClass() {
 	return CastTest.class;
 }