ECJ Compile Error: "The method sort(List<T>) in the type Collections is not applicable for the arguments ..." (eclipse-jdt#4040)

For now reduce the effect of eclipse-jdt#4023

Fixes eclipse-jdt#4039

Author: stephan-herrmann

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/lookup/ParameterizedTypeBinding.java

@@ -169,10 +169,15 @@ public boolean canBeInstantiated() {
 	}
 	@Override
 	public TypeBinding findSuperTypeOriginatingFrom(TypeBinding otherType) {
+		// see https://github.com/eclipse-jdt/eclipse.jdt.core/issues/4039 :
+		// if capture makes this and otherType equal, then treat that as the sought super type (for now)
+		TypeBinding capture = InferenceContext18.maybeCapture(this);
+		if (TypeBinding.equalsEquals(capture, otherType))
+			return capture;
+
 		if (otherType instanceof ReferenceBinding otherRef && TypeBinding.equalsEquals(this.type, otherRef.actualType()))
 			return this;
 
-		TypeBinding capture = InferenceContext18.maybeCapture(this);
 		if (capture != this) //$IDENTITY-COMPARISON$
 			return capture.findSuperTypeOriginatingFrom(otherType);
 		return super.findSuperTypeOriginatingFrom(otherType);

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/GenericsRegressionTest_1_8.java

@@ -6986,7 +6986,7 @@ public void testBug472851() {
 		"1. ERROR in Test.java (at line 10)\n" +
 		"	test(type);\n" +
 		"	^^^^\n" +
-		"The method test(List<L>) in the type Test is not applicable for the arguments (List<capture#1-of ? extends List<?>>)\n" +
+		"The method test(List<L>) in the type Test is not applicable for the arguments (List<capture#2-of ? extends List<?>>)\n" +
 		"----------\n");
 }
 public void testBug502350() {

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/GenericsRegressionTest_9.java

@@ -1211,6 +1211,30 @@ public static void main(String[] args) {
 			"""
 		});
 }
+public void testGH4039() {
+	runConformTest(new String[] {
+		"CollectionsSortReproducer.java",
+		"""
+		import java.util.Collection;
+		import java.util.Collections;
+		import java.util.Iterator;
+		import java.util.List;
+
+		public class CollectionsSortReproducer {
+			class Cranberry<T_Value> implements Comparable<Cranberry<T_Value>> {
+				@Override
+				public int compareTo(Cranberry<T_Value> o) { return 0; }
+			}
+
+			public static void main(String[] args) {
+				List<Cranberry<?>> l = Collections.emptyList();
+			    Collections.sort(l);
+			}
+		}
+		"""
+	});
+}
+
 public static Class<GenericsRegressionTest_9> testClass() {
 	return GenericsRegressionTest_9.class;
 }