Fix "res://" being replaced by resource packs in the editor and on Android

core/config/project_settings.cpp

@@ -472,13 +472,30 @@ void ProjectSettings::_emit_changed() {
 	emit_signal("settings_changed");
 }
 
-bool ProjectSettings::_load_resource_pack(const String &p_pack, bool p_replace_files, int p_offset) {
+bool ProjectSettings::load_resource_pack(const String &p_pack, bool p_replace_files, int p_offset) {
+	return ProjectSettings::_load_resource_pack(p_pack, p_replace_files, p_offset, false);
+}
+
+bool ProjectSettings::_load_resource_pack(const String &p_pack, bool p_replace_files, int p_offset, bool p_main_pack) {
 	if (PackedData::get_singleton()->is_disabled()) {
 		return false;
 	}
 
-	bool ok = PackedData::get_singleton()->add_pack(p_pack, p_replace_files, p_offset) == OK;
+	if (p_pack == "res://") {
+		// Loading the resource directory as a pack source is reserved for internal use only.
+		return false;
+	}
 
+	if (!p_main_pack && !using_datapack && !OS::get_singleton()->get_resource_dir().is_empty()) {
+		// Add the project's resource file system to PackedData so directory access keeps working when
+		// the game is running without a main pack, like in the editor or on Android.
+		PackedData::get_singleton()->add_pack_source(memnew(PackedSourceDirectory));
+		PackedData::get_singleton()->add_pack("res://", false, 0);
+		DirAccess::make_default<DirAccessPack>(DirAccess::ACCESS_RESOURCES);
+		using_datapack = true;
+	}
+
+	bool ok = PackedData::get_singleton()->add_pack(p_pack, p_replace_files, p_offset) == OK;
 	if (!ok) {
 		return false;
 	}
@@ -491,9 +508,11 @@ bool ProjectSettings::_load_resource_pack(const String &p_pack, bool p_replace_f
 		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;
+	// If the data pack was found, all directory access will be from here.
+	if (!using_datapack) {
+		DirAccess::make_default<DirAccessPack>(DirAccess::ACCESS_RESOURCES);
+		using_datapack = true;
+	}
 
 	return true;
 }
@@ -572,7 +591,7 @@ Error ProjectSettings::_setup(const String &p_path, const String &p_main_pack, b
 	// Attempt with a user-defined main pack first
 
 	if (!p_main_pack.is_empty()) {
-		bool ok = _load_resource_pack(p_main_pack);
+		bool ok = _load_resource_pack(p_main_pack, false, 0, true);
 		ERR_FAIL_COND_V_MSG(!ok, ERR_CANT_OPEN, vformat("Cannot open resource pack '%s'.", p_main_pack));
 
 		Error err = _load_settings_text_or_binary("res://project.godot", "res://project.binary");
@@ -591,7 +610,7 @@ Error ProjectSettings::_setup(const String &p_path, const String &p_main_pack, b
 		// and if so, we attempt loading it at the end.
 
 		// Attempt with PCK bundled into executable.
-		bool found = _load_resource_pack(exec_path);
+		bool found = _load_resource_pack(exec_path, false, 0, true);
 
 		// Attempt with exec_name.pck.
 		// (This is the usual case when distributing a Godot game.)
@@ -607,20 +626,20 @@ Error ProjectSettings::_setup(const String &p_path, const String &p_main_pack, b
 #ifdef MACOS_ENABLED
 		if (!found) {
 			// Attempt to load PCK from macOS .app bundle resources.
-			found = _load_resource_pack(OS::get_singleton()->get_bundle_resource_dir().path_join(exec_basename + ".pck")) || _load_resource_pack(OS::get_singleton()->get_bundle_resource_dir().path_join(exec_filename + ".pck"));
+			found = _load_resource_pack(OS::get_singleton()->get_bundle_resource_dir().path_join(exec_basename + ".pck"), false, 0, true) || _load_resource_pack(OS::get_singleton()->get_bundle_resource_dir().path_join(exec_filename + ".pck"), false, 0, true);
 		}
 #endif
 
 		if (!found) {
 			// Try to load data pack at the location of the executable.
 			// As mentioned above, we have two potential names to attempt.
-			found = _load_resource_pack(exec_dir.path_join(exec_basename + ".pck")) || _load_resource_pack(exec_dir.path_join(exec_filename + ".pck"));
+			found = _load_resource_pack(exec_dir.path_join(exec_basename + ".pck"), false, 0, true) || _load_resource_pack(exec_dir.path_join(exec_filename + ".pck"), false, 0, true);
 		}
 
 		if (!found) {
 			// If we couldn't find them next to the executable, we attempt
 			// the current working directory. Same story, two tests.
-			found = _load_resource_pack(exec_basename + ".pck") || _load_resource_pack(exec_filename + ".pck");
+			found = _load_resource_pack(exec_basename + ".pck", false, 0, true) || _load_resource_pack(exec_filename + ".pck", false, 0, true);
 		}
 
 		// If we opened our package, try and load our project.
@@ -1418,7 +1437,7 @@ void ProjectSettings::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("localize_path", "path"), &ProjectSettings::localize_path);
 	ClassDB::bind_method(D_METHOD("globalize_path", "path"), &ProjectSettings::globalize_path);
 	ClassDB::bind_method(D_METHOD("save"), &ProjectSettings::save);
-	ClassDB::bind_method(D_METHOD("load_resource_pack", "pack", "replace_files", "offset"), &ProjectSettings::_load_resource_pack, DEFVAL(true), DEFVAL(0));
+	ClassDB::bind_method(D_METHOD("load_resource_pack", "pack", "replace_files", "offset"), &ProjectSettings::load_resource_pack, DEFVAL(true), DEFVAL(0));
 
 	ClassDB::bind_method(D_METHOD("save_custom", "file"), &ProjectSettings::_save_custom_bnd);
 

core/config/project_settings.h

@@ -135,7 +135,8 @@ protected:
 
 	void _convert_to_last_version(int p_from_version);
 
-	bool _load_resource_pack(const String &p_pack, bool p_replace_files = true, int p_offset = 0);
+	bool load_resource_pack(const String &p_pack, bool p_replace_files, int p_offset);
+	bool _load_resource_pack(const String &p_pack, bool p_replace_files = true, int p_offset = 0, bool p_main_pack = false);
 
 	void _add_property_info_bind(const Dictionary &p_info);
 

core/io/file_access_pack.cpp

@@ -331,6 +331,44 @@ Ref<FileAccess> PackedSourcePCK::get_file(const String &p_path, PackedData::Pack
 
 //////////////////////////////////////////////////////////////////
 
+bool PackedSourceDirectory::try_open_pack(const String &p_path, bool p_replace_files, uint64_t p_offset) {
+	// Load with offset feature only supported for PCK files.
+	ERR_FAIL_COND_V_MSG(p_offset != 0, false, "Invalid PCK data. Note that loading files with a non-zero offset isn't supported with directories.");
+
+	if (p_path != "res://") {
+		return false;
+	}
+	add_directory(p_path, p_replace_files);
+	return true;
+}
+
+Ref<FileAccess> PackedSourceDirectory::get_file(const String &p_path, PackedData::PackedFile *p_file) {
+	Ref<FileAccess> ret = FileAccess::create_for_path(p_path);
+	ret->reopen(p_path, FileAccess::READ);
+	return ret;
+}
+
+void PackedSourceDirectory::add_directory(const String &p_path, bool p_replace_files) {
+	Ref<DirAccess> da = DirAccess::open(p_path);
+	if (da.is_null()) {
+		return;
+	}
+	da->set_include_hidden(true);
+
+	for (const String &file_name : da->get_files()) {
+		String file_path = p_path.path_join(file_name);
+		uint8_t md5[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+		PackedData::get_singleton()->add_path(p_path, file_path, 0, 0, md5, this, p_replace_files, false);
+	}
+
+	for (const String &sub_dir_name : da->get_directories()) {
+		String sub_dir_path = p_path.path_join(sub_dir_name);
+		add_directory(sub_dir_path, p_replace_files);
+	}
+}
+
+//////////////////////////////////////////////////////////////////
+
 Error FileAccessPack::open_internal(const String &p_path, int p_mode_flags) {
 	ERR_PRINT("Can't open pack-referenced file.");
 	return ERR_UNAVAILABLE;

core/io/file_access_pack.h

@@ -147,6 +147,14 @@ public:
 	virtual Ref<FileAccess> get_file(const String &p_path, PackedData::PackedFile *p_file) override;
 };
 
+class PackedSourceDirectory : public PackSource {
+	void add_directory(const String &p_path, bool p_replace_files);
+
+public:
+	virtual bool try_open_pack(const String &p_path, bool p_replace_files, uint64_t p_offset) override;
+	virtual Ref<FileAccess> get_file(const String &p_path, PackedData::PackedFile *p_file) override;
+};
+
 class FileAccessPack : public FileAccess {
 	PackedData::PackedFile pf;
 

doc/classes/ProjectSettings.xml

@@ -151,6 +151,7 @@
 				Loads the contents of the .pck or .zip file specified by [param pack] into the resource filesystem ([code]res://[/code]). Returns [code]true[/code] on success.
 				[b]Note:[/b] If a file from [param pack] shares the same path as a file already in the resource filesystem, any attempts to load that file will use the file from [param pack] unless [param replace_files] is set to [code]false[/code].
 				[b]Note:[/b] The optional [param offset] parameter can be used to specify the offset in bytes to the start of the resource pack. This is only supported for .pck files.
+				[b]Note:[/b] [DirAccess] will not show changes made to the contents of [code]res://[/code] after calling this function.
 			</description>
 		</method>
 		<method name="localize_path" qualifiers="const">