Fix implementation of ClassLoaderSupport.isNativeImageClassLoader

Author: olpaw

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/ClassLoaderSupportImpl.java

@@ -76,7 +76,23 @@ class ClassLoaderSupportImpl extends ClassLoaderSupport {
 
     @Override
     protected boolean isNativeImageClassLoaderImpl(ClassLoader loader) {
-        return loader == imageClassLoader || loader instanceof NativeImageSystemClassLoader;
+        if (loader == imageClassLoader) {
+            /* Trivial case */
+            return true;
+        }
+        if (loader == classLoaderSupport.classPathClassLoader) {
+            /*
+             * If imageClassLoader is a module classloader (building image with non-empty
+             * NativeImageClassLoaderSupport.imagemp), the passed loader could also be our
+             * classLoaderSupport.classPathClassLoader (building image with non-empty
+             * NativeImageClassLoaderSupport.imagecp).
+             */
+            return true;
+        }
+        if (loader instanceof NativeImageSystemClassLoader) {
+            return true;
+        }
+        return false;
     }
 
     @Override

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/NativeImageClassLoaderSupport.java

@@ -95,7 +95,7 @@ public class NativeImageClassLoaderSupport {
     private final EconomicMap<URI, EconomicSet<String>> packages;
     private final EconomicSet<String> emptySet;
 
-    private final URLClassLoader classPathClassLoader;
+    final URLClassLoader classPathClassLoader;
     private final ClassLoader modulePathClassLoader;
 
     public final ModuleFinder upgradeAndSystemModuleFinder;