Multiple scene editing *POTENTIALLY UNSTABLE*

-ability to edit multiple scenes at the same time
-resource internal IDs are now persistent, this makes multiple scene
editing possible but maaaaay result in file corruption bugs (tested and
could not find anything but possibility exists because core code
changed, report immediately if you find this).
-properly save settings, layout, etc when edited
-script editing is independent from scene editing now
-show a yellow box when a script belongs to the scene

9 files changed, 168 insertions, 18 deletions

diff --git a/core/io/resource_format_binary.cpp b/core/io/resource_format_binary.cpp
index 9fb17bcffb..0f6f8a74b1 100644
--- a/core/io/resource_format_binary.cpp
+++ b/core/io/resource_format_binary.cpp
@@ -663,14 +663,18 @@ Error ResourceInteractiveLoaderBinary::poll(){
 
 	//maybe it is loaded already
 	String path;
+	int subindex=0;
 
 
 
 	if (!main) {
 
 		path=internal_resources[s].path;
-		if (path.begins_with("local://"))
-			path=path.replace("local://",res_path+"::");
+		if (path.begins_with("local://")) {
+			path=path.replace_first("local://","");
+			subindex = path.to_int();
+			path=res_path+"::"+path;
+		}
 
 
 
@@ -709,6 +713,7 @@ Error ResourceInteractiveLoaderBinary::poll(){
 	RES res = RES( r );
 
 	r->set_path(path);
+	r->set_subindex(subindex);
 
 	int pc = f->get_32();
 
@@ -1434,14 +1439,14 @@ void ResourceFormatSaverBinaryInstance::write_variant(const Variant& p_property,
 				save_unicode_string(path);
 			} else {
 
-				if (!resource_map.has(res)) {
+				if (!resource_set.has(res)) {
 					f->store_32(OBJECT_EMPTY);
 					ERR_EXPLAIN("Resource was not pre cached for the resource section, bug?");
 					ERR_FAIL();
 				}
 
 				f->store_32(OBJECT_INTERNAL_RESOURCE);
-				f->store_32(resource_map[res]);
+				f->store_32(res->get_subindex());
 				//internal resource
 			}
 
@@ -1598,7 +1603,7 @@ void ResourceFormatSaverBinaryInstance::_find_resources(const Variant& p_variant
 			}
 
 
-			if (resource_map.has(res))
+			if (resource_set.has(res))
 				return;
 
 			List<PropertyInfo> property_list;
@@ -1613,7 +1618,7 @@ void ResourceFormatSaverBinaryInstance::_find_resources(const Variant& p_variant
 				}
 			}
 
-			resource_map[ res ] = saved_resources.size();
+			resource_set.insert(res);
 			saved_resources.push_back(res);
 
 		} break;
@@ -1846,11 +1851,42 @@ Error ResourceFormatSaverBinaryInstance::save(const String &p_path,const RES& p_
 	// save internal resource table
 	f->store_32(saved_resources.size()); //amount of internal resources
 	Vector<uint64_t> ofs_pos;
+	Set<int> used_indices;
+
+	for(List<RES>::Element *E=saved_resources.front();E;E=E->next()) {
+
+		RES r = E->get();
+		if (r->get_path()=="" || r->get_path().find("::")!=-1) {
+
+			if (r->get_subindex()!=0) {
+				if (used_indices.has(r->get_subindex())) {
+					r->set_subindex(0); //repeated
+				} else {
+					used_indices.insert(r->get_subindex());
+				}
+			}
+		}
+
+	}
+
+
 	for(List<RES>::Element *E=saved_resources.front();E;E=E->next()) {
 
+
 		RES r = E->get();
 		if (r->get_path()=="" || r->get_path().find("::")!=-1) {
-			save_unicode_string("local://"+itos(ofs_pos.size()));
+			if (r->get_subindex()==0) {
+				int new_subindex=1;
+				if (used_indices.size()) {
+					new_subindex=used_indices.back()->get()+1;
+				}
+
+				r->set_subindex(new_subindex);
+				used_indices.insert(new_subindex);
+
+			}
+
+			save_unicode_string("local://"+itos(r->get_subindex()));
 			if (takeover_paths) {
 				r->set_path(p_path+"::"+itos(ofs_pos.size()),true);
 			}
diff --git a/core/io/resource_format_binary.h b/core/io/resource_format_binary.h
index ab2e640a86..da415d97a5 100644
--- a/core/io/resource_format_binary.h
+++ b/core/io/resource_format_binary.h
@@ -129,7 +129,7 @@ class ResourceFormatSaverBinaryInstance  {
 	int bin_meta_idx;
 	FileAccess *f;
 	String magic;
-	Map<RES,int> resource_map;
+	Set<RES> resource_set;
 	Map<StringName,int> string_map;
 	Vector<StringName> strings;
 
diff --git a/core/io/resource_format_xml.cpp b/core/io/resource_format_xml.cpp
index 3c100d375a..36746a4111 100644
--- a/core/io/resource_format_xml.cpp
+++ b/core/io/resource_format_xml.cpp
@@ -1466,6 +1466,7 @@ Error ResourceInteractiveLoaderXML::poll() {
 
 	String type;
 	String path;
+	int subres=0;
 
 	if (!main) {
 		//loading resource
@@ -1476,11 +1477,15 @@ Error ResourceInteractiveLoaderXML::poll() {
 		ERR_EXPLAIN(local_path+":"+itos(get_current_line())+": <resource> missing 'type' field.");
 		ERR_FAIL_COND_V(!tag->args.has("type"),ERR_FILE_CORRUPT);
 		path=tag->args["path"];
+
 		error=OK;
 
 		if (path.begins_with("local://")) {
 			//built-in resource (but really external)
-			path=path.replace("local://",local_path+"::");
+
+			path=path.replace("local://","");
+			subres=path.to_int();
+			path=local_path+"::"+path;
 		}
 
 
@@ -1519,6 +1524,7 @@ Error ResourceInteractiveLoaderXML::poll() {
 	res = RES( r );
 	if (path!="")
 		r->set_path(path);
+	r->set_subindex(subres);
 
 	//load properties
 
@@ -2029,9 +2035,9 @@ void ResourceFormatSaverXMLInstance::write_property(const String& p_name,const V
 
 				//internal resource
 				ERR_EXPLAIN("Resource was not pre cached for the resource section, bug?");
-				ERR_FAIL_COND(!resource_map.has(res));
+				ERR_FAIL_COND(!resource_set.has(res));
 
-				params+=" path=\"local://"+itos(resource_map[res])+"\"";
+				params+=" path=\"local://"+itos(res->get_subindex())+"\"";
 			}
 
 		} break;
@@ -2443,7 +2449,7 @@ void ResourceFormatSaverXMLInstance::_find_resources(const Variant& p_variant,bo
 				return;
 			}
 
-			if (resource_map.has(res))
+			if (resource_set.has(res))
 				return;
 
 			List<PropertyInfo> property_list;
@@ -2466,7 +2472,7 @@ void ResourceFormatSaverXMLInstance::_find_resources(const Variant& p_variant,bo
 				I=I->next();
 			}
 
-			resource_map[ res ] = resource_map.size(); //saved after, so the childs it needs are available when loaded
+			resource_set.insert( res ); //saved after, so the childs it needs are available when loaded
 			saved_resources.push_back(res);
 
 		} break;
@@ -2537,12 +2543,27 @@ Error ResourceFormatSaverXMLInstance::save(const String &p_path,const RES& p_res
 		write_string("\n",false);
 	}
 
+	Set<int> used_indices;
+
+	for(List<RES>::Element *E=saved_resources.front();E;E=E->next()) {
+
+		RES res = E->get();
+		if (E->next() && (res->get_path()=="" || res->get_path().find("::") != -1 )) {
 
+			if (res->get_subindex()!=0) {
+				if (used_indices.has(res->get_subindex())) {
+					res->set_subindex(0); //repeated
+				} else {
+					used_indices.insert(res->get_subindex());
+				}
+			}
+		}
+	}
 
 	for(List<RES>::Element *E=saved_resources.front();E;E=E->next()) {
 
 		RES res = E->get();
-		ERR_CONTINUE(!resource_map.has(res));
+		ERR_CONTINUE(!resource_set.has(res));
 		bool main = (E->next()==NULL);
 
 		write_tabs();
@@ -2552,7 +2573,18 @@ Error ResourceFormatSaverXMLInstance::save(const String &p_path,const RES& p_res
 		else if (res->get_path().length() && res->get_path().find("::") == -1 )
 			enter_tag("resource","type=\""+res->get_type()+"\" path=\""+res->get_path()+"\""); //bundled
 		else {
-			int idx = resource_map[res];
+
+			if (res->get_subindex()==0) {
+				int new_subindex=1;
+				if (used_indices.size()) {
+					new_subindex=used_indices.back()->get()+1;
+				}
+
+				res->set_subindex(new_subindex);
+				used_indices.insert(new_subindex);
+			}
+
+			int idx = res->get_subindex();
 			enter_tag("resource","type=\""+res->get_type()+"\" path=\"local://"+itos(idx)+"\"");
 			if (takeover_paths) {
 				res->set_path(p_path+"::"+itos(idx),true);
diff --git a/core/io/resource_format_xml.h b/core/io/resource_format_xml.h
index 711b607668..d5ba9eb800 100644
--- a/core/io/resource_format_xml.h
+++ b/core/io/resource_format_xml.h
@@ -123,7 +123,7 @@ class ResourceFormatSaverXMLInstance  {
 	bool skip_editor;
 	FileAccess *f;
 	int depth;
-	Map<RES,int> resource_map;
+	Set<RES> resource_set;
 	List<RES> saved_resources;
 	List<RES> external_resources;
 
diff --git a/core/object.cpp b/core/object.cpp
index 83a6dada80..cdb2c6517a 100644
--- a/core/object.cpp
+++ b/core/object.cpp
@@ -34,6 +34,7 @@
 #include "core_string_names.h"
 #include "translation.h"
 #include "os/os.h"
+#include "resource.h"
 
 #ifdef DEBUG_ENABLED
 
@@ -1464,6 +1465,63 @@ StringName Object::tr(const StringName& p_message) const {
 
 }
 
+
+void Object::_clear_internal_resource_paths(const Variant &p_var) {
+
+	switch(p_var.get_type()) {
+
+		case Variant::OBJECT: {
+
+			RES r = p_var;
+			if (!r.is_valid())
+				return;
+
+			if (!r->get_path().begins_with("res://") || r->get_path().find("::")==-1)
+				return; //not an internal resource
+
+			Object *object=p_var;
+			if (!object)
+				return;
+
+			r->set_path("");
+			r->clear_internal_resource_paths();
+		} break;
+		case Variant::ARRAY: {
+
+			Array a=p_var;
+			for(int i=0;i<a.size();i++) {
+				_clear_internal_resource_paths(a[i]);
+			}
+
+		} break;
+		case Variant::DICTIONARY: {
+
+			Dictionary d=p_var;
+			List<Variant> keys;
+			d.get_key_list(&keys);
+
+			for (List<Variant>::Element *E=keys.front();E;E=E->next()) {
+
+				_clear_internal_resource_paths(E->get());
+				_clear_internal_resource_paths(d[E->get()]);
+			}
+		} break;
+	}
+
+}
+
+void Object::clear_internal_resource_paths() {
+
+	List<PropertyInfo> pinfo;
+
+	get_property_list(&pinfo);
+
+	for(List<PropertyInfo>::Element *E=pinfo.front();E;E=E->next()) {
+
+		_clear_internal_resource_paths(get(E->get().name));
+	}
+}
+
 void Object::_bind_methods() {
 
 	ObjectTypeDB::bind_method(_MD("get_type"),&Object::get_type);
diff --git a/core/object.h b/core/object.h
index 8d1f8ebc5a..9680af924a 100644
--- a/core/object.h
+++ b/core/object.h
@@ -451,6 +451,8 @@ protected:
 	Array _get_property_list_bind() const;
 	Array _get_method_list_bind() const;
 
+	void _clear_internal_resource_paths(const Variant &p_var);
+
 public: //should be protected, but bug in clang++
 	static void initialize_type();
 	_FORCE_INLINE_ static void register_custom_data_to_otdb() {};
@@ -599,6 +601,9 @@ public:
 
 	_FORCE_INLINE_ void set_message_translation(bool p_enable) { _can_translate=p_enable; }
 	_FORCE_INLINE_ bool can_translate_messages() const { return _can_translate; }
+
+	void clear_internal_resource_paths();
+
 	Object();	
 	virtual ~Object();
 
@@ -651,6 +656,8 @@ public:
 
 #endif
 
+
+
 };
 
 //needed by macros
diff --git a/core/resource.cpp b/core/resource.cpp
index 6e65693350..6967599f96 100644
--- a/core/resource.cpp
+++ b/core/resource.cpp
@@ -195,6 +195,17 @@ String Resource::get_path() const {
 	return path_cache;
 }
 
+void Resource::set_subindex(int p_sub_index) {
+
+	subindex=p_sub_index;
+}
+
+int Resource::get_subindex() const{
+
+	return subindex;
+}
+
+
 void Resource::set_name(const String& p_name) {
 
 	name=p_name;
@@ -326,6 +337,7 @@ Resource::Resource() {
 	last_modified_time=0;
 #endif
 
+	subindex=0;
 }
 
 
diff --git a/core/resource.h b/core/resource.h
index cf7ffcbd2c..9d9c445e1d 100644
--- a/core/resource.h
+++ b/core/resource.h
@@ -99,6 +99,7 @@ friend class ResourceCache;
 	
 	String name;
 	String path_cache;
+	int subindex;
 
 	virtual bool _use_builtin_script() const { return true; }
 
@@ -132,6 +133,9 @@ public:
 	void set_path(const String& p_path,bool p_take_over=false);
 	String get_path() const;
 
+	void set_subindex(int p_sub_index);
+	int get_subindex() const;
+
 	Ref<Resource> duplicate(bool p_subresources=false);
 
 	void set_import_metadata(const Ref<ResourceImportMetadata>& p_metadata);
diff --git a/core/undo_redo.cpp b/core/undo_redo.cpp
index 5e7df3be7e..90ca397275 100644
--- a/core/undo_redo.cpp
+++ b/core/undo_redo.cpp
@@ -282,6 +282,7 @@ void UndoRedo::undo() {
 		return; //nothing to redo
 	_process_operation_list(actions[current_action].undo_ops.front());
 	current_action--;
+	version--;
 }
 
 void UndoRedo::clear_history() {
@@ -292,7 +293,7 @@ void UndoRedo::clear_history() {
 	while(actions.size())
 		_pop_history_tail();
 
-	version++;
+	//version++;
 }
 
 String UndoRedo::get_current_action_name() const {
@@ -326,7 +327,7 @@ void UndoRedo::set_commit_notify_callback(CommitNotifyCallback p_callback,void*
 
 UndoRedo::UndoRedo() {
 
-	version=0;
+	version=1;
 	action_level=0;
 	current_action=-1;
 	max_steps=-1;