Fix some bounds and signatures

Author: mickaelistria

org.eclipse.jdt.core.javac/src/org/eclipse/jdt/internal/SignatureUtils.java

@@ -121,16 +121,12 @@ public static String getSignature(ITypeBinding typeBinding) {
 			return Signature.createArraySignature(getSignature(typeBinding.getComponentType()), 1);
 		}
 		if (typeBinding.isWildcardType()) {
-		  var upper = typeBinding.getTypeBounds();
-		  if (upper != null && upper.length > 0) {
-		    return Signature.C_EXTENDS + Stream.of(upper).map(SignatureUtils::getSignature).collect(Collectors.joining());
-		  }
-		  var lower = typeBinding.getWildcard();
-		  if (lower != null && lower != typeBinding) {
-		    return Signature.C_SUPER + SignatureUtils.getSignature(lower);
-		  }
-			// TODO if typeBinding.getBounds(): C_EXTENDS, C_SUPER
-			return Character.toString(Signature.C_STAR);
+			var bounds = typeBinding.getTypeBounds();
+			if (bounds.length == 0) {
+				return Character.toString(Signature.C_STAR);
+			}
+			return (typeBinding.isUpperbound() ? Signature.C_EXTENDS : Signature.C_SUPER)
+				+ Stream.of(bounds).map(SignatureUtils::getSignature).collect(Collectors.joining());
 		}
 		ITypeBinding[] typeBounds = typeBinding.getTypeBounds();
 		if (typeBinding.isTypeVariable() || typeBinding.isWildcardType()) {

org.eclipse.jdt.core.javac/src/org/eclipse/jdt/internal/javac/dom/JavacTypeBinding.java

@@ -1438,7 +1438,7 @@ public ITypeBinding[] getTypeBounds() {
 					return new ITypeBinding[0];
 				}
 			}
-			Type bounds = typeVar.getUpperBound();
+			Type bounds = typeVar.isSuperBound() ? typeVar.getLowerBound() : typeVar.getUpperBound();
 			if (bounds instanceof IntersectionClassType intersectionType) {
 				return intersectionType.getBounds().stream() //
 						.filter(Type.class::isInstance) //
@@ -1450,10 +1450,7 @@ public ITypeBinding[] getTypeBounds() {
 		} else if (this.type instanceof WildcardType wildcardType) {
 			boolean isUnbound = wildcardType.isUnbound();
 			boolean isSuperBound = wildcardType.isSuperBound();
-			if (wildcardType.type instanceof Type.TypeVar typeVar) {
-				return this.resolver.bindings.getTypeVariableBinding(typeVar, this.typeSymbol).getTypeBounds();
-			}
-			return new ITypeBinding[] { isUnbound || isSuperBound ?
+			return new ITypeBinding[] { isUnbound ?
 					this.resolver.resolveWellKnownType(Object.class.getName()) :
 					this.resolver.bindings.getTypeBinding(wildcardType.type) };
 		}
@@ -1688,7 +1685,7 @@ public boolean isTypeVariable() {
 
 	@Override
 	public boolean isUpperbound() {
-		return this.type.isExtendsBound();
+		return this.type != null && this.type.isExtendsBound();
 	}
 
 	@Override