6 files changed, 72 insertions, 13 deletions

diff --git a/core/config/project_settings.cpp b/core/config/project_settings.cpp
index f5baf1a27e..ce7fa1074b 100644
--- a/core/config/project_settings.cpp
+++ b/core/config/project_settings.cpp
@@ -38,6 +38,8 @@
 #include "core/io/file_access.h"
 #include "core/io/file_access_pack.h"
 #include "core/io/marshalls.h"
+#include "core/io/resource_uid.h"
+#include "core/object/script_language.h"
 #include "core/os/keyboard.h"
 #include "core/templates/rb_set.h"
 #include "core/variant/typed_array.h"
@@ -478,6 +480,14 @@ bool ProjectSettings::_load_resource_pack(const String &p_pack, bool p_replace_f
 		return false;
 	}
 
+	if (project_loaded) {
+		// This pack may have declared new global classes (make sure they are picked up).
+		refresh_global_class_list();
+
+		// This pack may have defined new UIDs, make sure they are cached.
+		ResourceUID::get_singleton()->load_from_cache(false);
+	}
+
 	//if data.pck is found, all directory access will be from here
 	DirAccess::make_default<DirAccessPack>(DirAccess::ACCESS_RESOURCES);
 	using_datapack = true;
@@ -1189,6 +1199,19 @@ Variant ProjectSettings::get_setting(const String &p_setting, const Variant &p_d
 	}
 }
 
+void ProjectSettings::refresh_global_class_list() {
+	// This is called after mounting a new PCK file to pick up class changes.
+	is_global_class_list_loaded = false; // Make sure we read from the freshly mounted PCK.
+	Array script_classes = get_global_class_list();
+	for (int i = 0; i < script_classes.size(); i++) {
+		Dictionary c = script_classes[i];
+		if (!c.has("class") || !c.has("language") || !c.has("path") || !c.has("base")) {
+			continue;
+		}
+		ScriptServer::add_global_class(c["class"], c["base"], c["language"], c["path"]);
+	}
+}
+
 TypedArray<Dictionary> ProjectSettings::get_global_class_list() {
 	if (is_global_class_list_loaded) {
 		return global_class_list;
diff --git a/core/config/project_settings.h b/core/config/project_settings.h
index 252b10bd3a..1bad76acb1 100644
--- a/core/config/project_settings.h
+++ b/core/config/project_settings.h
@@ -154,6 +154,7 @@ public:
 	void set_setting(const String &p_setting, const Variant &p_value);
 	Variant get_setting(const String &p_setting, const Variant &p_default_value = Variant()) const;
 	TypedArray<Dictionary> get_global_class_list();
+	void refresh_global_class_list();
 	void store_global_class_list(const Array &p_classes);
 	String get_global_class_list_path() const;
 
diff --git a/core/io/resource_uid.cpp b/core/io/resource_uid.cpp
index edff3e1f14..c14121a53b 100644
--- a/core/io/resource_uid.cpp
+++ b/core/io/resource_uid.cpp
@@ -169,14 +169,16 @@ Error ResourceUID::save_to_cache() {
 	return OK;
 }
 
-Error ResourceUID::load_from_cache() {
+Error ResourceUID::load_from_cache(bool p_reset) {
 	Ref<FileAccess> f = FileAccess::open(get_cache_file(), FileAccess::READ);
 	if (f.is_null()) {
 		return ERR_CANT_OPEN;
 	}
 
 	MutexLock l(mutex);
-	unique_ids.clear();
+	if (p_reset) {
+		unique_ids.clear();
+	}
 
 	uint32_t entry_count = f->get_32();
 	for (uint32_t i = 0; i < entry_count; i++) {
diff --git a/core/io/resource_uid.h b/core/io/resource_uid.h
index 22561c5c03..e56b89f603 100644
--- a/core/io/resource_uid.h
+++ b/core/io/resource_uid.h
@@ -73,7 +73,7 @@ public:
 	String get_id_path(ID p_id) const;
 	void remove_id(ID p_id);
 
-	Error load_from_cache();
+	Error load_from_cache(bool p_reset);
 	Error save_to_cache();
 	Error update_cache();
 
diff --git a/core/object/script_language.cpp b/core/object/script_language.cpp
index 693c6819d4..14894e1710 100644
--- a/core/object/script_language.cpp
+++ b/core/object/script_language.cpp
@@ -325,12 +325,24 @@ void ScriptServer::global_classes_clear() {
 
 void ScriptServer::add_global_class(const StringName &p_class, const StringName &p_base, const StringName &p_language, const String &p_path) {
 	ERR_FAIL_COND_MSG(p_class == p_base || (global_classes.has(p_base) && get_global_class_native_base(p_base) == p_class), "Cyclic inheritance in script class.");
-	GlobalScriptClass g;
-	g.language = p_language;
-	g.path = p_path;
-	g.base = p_base;
-	global_classes[p_class] = g;
-	inheriters_cache_dirty = true;
+	GlobalScriptClass *existing = global_classes.getptr(p_class);
+	if (existing) {
+		// Update an existing class (only set dirty if something changed).
+		if (existing->base != p_base || existing->path != p_path || existing->language != p_language) {
+			existing->base = p_base;
+			existing->path = p_path;
+			existing->language = p_language;
+			inheriters_cache_dirty = true;
+		}
+	} else {
+		// Add new class.
+		GlobalScriptClass g;
+		g.language = p_language;
+		g.path = p_path;
+		g.base = p_base;
+		global_classes[p_class] = g;
+		inheriters_cache_dirty = true;
+	}
 }
 
 void ScriptServer::remove_global_class(const StringName &p_class) {
diff --git a/core/variant/callable.cpp b/core/variant/callable.cpp
index 6bad6f5a5b..47271118a0 100644
--- a/core/variant/callable.cpp
+++ b/core/variant/callable.cpp
@@ -92,10 +92,31 @@ Error Callable::rpcp(int p_id, const Variant **p_arguments, int p_argcount, Call
 		r_call_error.expected = 0;
 		return ERR_UNCONFIGURED;
 	} else if (!is_custom()) {
-		r_call_error.error = CallError::CALL_ERROR_INVALID_METHOD;
-		r_call_error.argument = 0;
-		r_call_error.expected = 0;
-		return ERR_UNCONFIGURED;
+		Object *obj = ObjectDB::get_instance(ObjectID(object));
+#ifdef DEBUG_ENABLED
+		if (!obj || !obj->is_class("Node")) {
+			r_call_error.error = CallError::CALL_ERROR_INSTANCE_IS_NULL;
+			r_call_error.argument = 0;
+			r_call_error.expected = 0;
+			return ERR_UNCONFIGURED;
+		}
+#endif
+
+		int argcount = p_argcount + 2;
+		const Variant **argptrs = (const Variant **)alloca(sizeof(Variant *) * argcount);
+		const Variant args[2] = { p_id, method };
+
+		argptrs[0] = &args[0];
+		argptrs[1] = &args[1];
+		for (int i = 0; i < p_argcount; ++i) {
+			argptrs[i + 2] = p_arguments[i];
+		}
+
+		CallError tmp;
+		Error err = (Error)obj->callp(SNAME("rpc_id"), argptrs, argcount, tmp).operator int64_t();
+
+		r_call_error.error = Callable::CallError::CALL_OK;
+		return err;
 	} else {
 		return custom->rpc(p_id, p_arguments, p_argcount, r_call_error);
 	}