--- old/src/hotspot/share/classfile/moduleEntry.cpp	2020-06-23 12:35:20.819198806 -0700
+++ new/src/hotspot/share/classfile/moduleEntry.cpp	2020-06-23 12:35:20.639192031 -0700
@@ -57,7 +57,7 @@
   if (location != NULL) {
     location->increment_refcount();
     CDS_ONLY(if (UseSharedSpaces) {
-        _shared_path_index = FileMapInfo::get_module_shared_path_index(_location);
+        _shared_path_index = FileMapInfo::get_module_shared_path_index(location);
       });
   }
 }
--- old/src/hotspot/share/classfile/moduleEntry.hpp	2020-06-23 12:35:21.655230276 -0700
+++ new/src/hotspot/share/classfile/moduleEntry.hpp	2020-06-23 12:35:21.411221091 -0700
@@ -69,7 +69,7 @@
   GrowableArray<ModuleEntry*>* _reads; // list of modules that are readable by this module
   Symbol* _version;                    // module version number
   Symbol* _location;                   // module location
-  CDS_ONLY(int _shared_path_index;)    // >0 if this classes in this module are in CDS archive
+  CDS_ONLY(int _shared_path_index;)    // >=0 if classes in this module are in CDS archive
   bool _can_read_all_unnamed;
   bool _has_default_read_edges;        // JVMTI redefine/retransform support
   bool _must_walk_reads;               // walk module's reads list at GC safepoints to purge out dead modules
@@ -156,6 +156,7 @@
 
   void set_is_patched() {
       _is_patched = true;
+      CDS_ONLY(_shared_path_index = -1); // Mark all shared classes in this module invisible.
   }
   bool is_patched() {
       return _is_patched;
--- old/src/hotspot/share/classfile/systemDictionary.cpp	2020-06-23 12:35:22.335255874 -0700
+++ new/src/hotspot/share/classfile/systemDictionary.cpp	2020-06-23 12:35:22.107247291 -0700
@@ -1353,10 +1353,11 @@
 }
 
 bool SystemDictionary::is_shared_class_visible_impl(Symbol* class_name,
-                                               InstanceKlass* ik,
-                                               PackageEntry* pkg_entry,
-                                               Handle class_loader, TRAPS) {
+                                                    InstanceKlass* ik,
+                                                    PackageEntry* pkg_entry,
+                                                    Handle class_loader, TRAPS) {
   int scp_index = ik->shared_classpath_index();
+  assert(!ik->is_shared_unregistered_class(), "this function should be called for built-in classes only");
   assert(scp_index >= 0, "must be");
   SharedClassPathEntry* scp_entry = FileMapInfo::shared_path(scp_index);
   if (!Universe::is_module_initialized()) {
@@ -1375,6 +1376,9 @@
     if (should_be_in_named_module) {
       // Is the module loaded from the same location as during dump time?
       visible = mod_entry->shared_path_index() == scp_index;
+      if (visible) {
+        assert(!mod_entry->is_patched(), "cannot load archived classes for patched module");
+      }
     } else {
       // During dump time, this class was in a named module, but at run time, this class should be
       // in an unnamed module.
--- old/src/hotspot/share/classfile/systemDictionary.hpp	2020-06-23 12:35:23.195288247 -0700
+++ new/src/hotspot/share/classfile/systemDictionary.hpp	2020-06-23 12:35:22.943278761 -0700
@@ -629,9 +629,10 @@
   static bool is_shared_class_visible(Symbol* class_name, InstanceKlass* ik,
                                       PackageEntry* pkg_entry,
                                       Handle class_loader, TRAPS);
-  static bool is_shared_class_visible_impl(Symbol* class_name, InstanceKlass* ik,
-                                          PackageEntry* pkg_entry,
-                                          Handle class_loader, TRAPS);
+  static bool is_shared_class_visible_impl(Symbol* class_name,
+                                           InstanceKlass* ik,
+                                           PackageEntry* pkg_entry,
+                                           Handle class_loader, TRAPS);
   static bool is_shared_class_visible_impl_old(Symbol* class_name, InstanceKlass* ik,
                                                PackageEntry* pkg_entry,
                                                Handle class_loader,
--- old/src/hotspot/share/memory/filemap.cpp	2020-06-23 12:35:23.995318361 -0700
+++ new/src/hotspot/share/memory/filemap.cpp	2020-06-23 12:35:23.763309628 -0700
@@ -380,6 +380,7 @@
   }
 }
 
+
 void SharedClassPathEntry::metaspace_pointers_do(MetaspaceClosure* it) {
   it->push(&_name);
   it->push(&_manifest);
--- old/test/hotspot/jtreg/runtime/cds/appcds/jigsaw/PatchModule/Simple.java	2020-06-23 12:35:24.807348927 -0700
+++ new/test/hotspot/jtreg/runtime/cds/appcds/jigsaw/PatchModule/Simple.java	2020-06-23 12:35:24.591340796 -0700
@@ -76,5 +76,20 @@
             "-Xlog:class+path=info",
             "PatchMain", "javax.naming.spi.NamingManager")
             .assertSilentlyDisabledCDS(0, "I pass!");
+
+        // ========================================
+        System.out.println("Dump again without --patch-module");
+        output =
+            TestCommon.dump(null,
+                TestCommon.list("javax/naming/spi/NamingManager"));
+        output.shouldHaveExitValue(0);
+
+        TestCommon.run(
+            "-XX:+UnlockDiagnosticVMOptions",
+            "--patch-module=java.naming=" + moduleJar,
+            "-Xlog:class+load",
+            "-Xlog:class+path=info",
+            "PatchMain", "javax.naming.spi.NamingManager")
+            .assertSilentlyDisabledCDS(0, "I pass!");       
     }
 }