--- old/src/hotspot/share/classfile/classLoader.hpp	2019-03-13 08:49:07.823253459 -0700
+++ new/src/hotspot/share/classfile/classLoader.hpp	2019-03-13 08:49:07.523249772 -0700
@@ -26,6 +26,7 @@
 #define SHARE_CLASSFILE_CLASSLOADER_HPP
 
 #include "jimage.hpp"
+#include "runtime/arguments.hpp"
 #include "runtime/handles.hpp"
 #include "runtime/perfData.hpp"
 #include "utilities/exceptions.hpp"
@@ -34,7 +35,12 @@
 // The VM class loader.
 #include <sys/stat.h>
 
-// Name of boot "modules" image
+// Name of boot "modules" image. This macro may be used with caution.
+//
+// For most of use cases, ClassLoader::modules_image_identity(), which gives the
+// canonical path should be used. When dealing with the system boot path string
+// that's set up by os::set_boot_path(), then the canonical name cannot be
+// used and MODULES_IMAGE_NAME should be used directly.
 #define  MODULES_IMAGE_NAME "modules"
 
 // Class path entry (directory or zip file)
@@ -217,6 +223,9 @@
   // Last entry in linked list of appended ClassPathEntry instances
   static ClassPathEntry* _last_append_entry;
 
+  // The modules image identity obtained from the canonical path.
+  static const char* _modules_image_identity;
+
   // Info used by CDS
   CDS_ONLY(static SharedPathsMiscInfo * _shared_paths_misc_info;)
 
@@ -439,7 +448,14 @@
   // distinguish from a class_name with no package name, as both cases have a NULL return value
   static const char* package_from_name(const char* const class_name, bool* bad_class_name = NULL);
 
-  static bool is_modules_image(const char* name) { return string_ends_with(name, MODULES_IMAGE_NAME); }
+  static const char* modules_image_identity() { return _modules_image_identity; }
+  static bool is_modules_image(const char* name) {
+    if (Arguments::has_jimage()) {
+      assert(modules_image_identity() != NULL, "must be set");
+      return strcmp(name, modules_image_identity()) == 0;
+    }
+    return false;
+  }
 
   // Debugging
   static void verify()              PRODUCT_RETURN;