Use the bound of the TypeVariable as search class

Treiblesschorle · ctrueden · commit 0b1df599556d · 2019-04-18T12:02:50.000-05:00
Instead of using the TypeVariable itself, we need to use the resolved
bound of it. The TypeVariable itself may not be unbounded, but we may
already have found bounds for it.

Moreover, if arg or its direct supertypes are not parameterized
(Types.param() will return null) we can return false here.
diff --git a/src/main/java/org/scijava/util/Types.java b/src/main/java/org/scijava/util/Types.java
@@ -944,7 +944,12 @@ private static boolean satisfiesTypeVariable(final Type arg,
 				final ParameterizedType paramBoundType = (ParameterizedType) paramBound;
 				final Type[] paramBoundTypes = paramBoundType.getActualTypeArguments();
 				for (int i = 0; i < paramBoundTypes.length; i++) {
-					final Type argType = Types.param(arg, Types.raw(param), i);
+					// Get the type parameter of arg from the bound type which we know
+					// is parameterized.
+					final Type argType = Types.param(arg, Types.raw(paramBoundType), i);
+					if (argType == null) {
+						return false;
+					}
 					if (paramBoundTypes[i] instanceof TypeVariable<?> &&
 						!satisfiesTypeParameter(argType,
 							(TypeVariable<?>) paramBoundTypes[i], typeBounds)) return false;
