Implementation of setinstancevar (#6374)

* Added getinstancevar alias of getvariableofinstance
* Fixed #6353

Thanks to @Everade 
Co-authored-by: Lemongrass3110 <lemongrass@kstp.at>

doc/script_commands.txt

@@ -482,7 +482,7 @@ nothing  - A permanent variable attached to the character, the default variable
 "'"      - An instance variable.
            These are used with the instancing system and are unique to each
            instance type. Can be accessed from inside the instance or by calling
-           'getvariableofinstance'.
+           'getinstancevar'.
 "#"      - A permanent local account variable.
            They are stored by char-server in the `acc_reg_num` table and
            `acc_reg_str`.
@@ -9419,17 +9419,30 @@ Examples:
 
 ---------------------------------------
 
-*getvariableofinstance(<variable>,<instance id>);
+*getinstancevar(<variable>,<instance id>);
 
 Returns a reference to an instance variable (' prefix) of the specific instance ID.
 This can only be used to get ' variables.
 
 Examples:
 	// This will set the .@s variable to the value of 'var variable of the specific instance ID.
-	set .@s, getvariableofinstance('var, instance_id(IM_PARTY));
+	set .@s, getinstancevar('var, instance_id(IM_PARTY));
 
 	// This will set the 'var variable of the specific instance ID to 1.
-	set getvariableofinstance('var, instance_id(IM_GUILD)), 1;
+	set getinstancevar('var, instance_id(IM_GUILD)), 1;
+
+---------------------------------------
+
+*setinstancevar(<variable>,<value>,<instance id>);
+
+This command will set an instance variable to the value that the expression results in.
+See 'set' command for more information.
+
+Returns the variable reference.
+
+Examples:
+	// This will set the 'var variable of the specific instance ID to 9.
+	setinstancevar('var, 9, instance_id(IM_GUILD));
 
 ---------------------------------------
 

src/map/script.cpp

@@ -25243,13 +25243,13 @@ BUILDIN_FUNC(achievement_condition){
 /// Returns a reference to a variable of the specific instance ID.
 /// Returns 0 if an error occurs.
 ///
-/// getvariableofinstance(<variable>, <instance ID>) -> <reference>
-BUILDIN_FUNC(getvariableofinstance)
+/// getinstancevar(<variable>, <instance ID>) -> <reference>
+BUILDIN_FUNC(getinstancevar)
 {
 	struct script_data* data = script_getdata(st, 2);
 
 	if (!data_isreference(data)) {
-		ShowError("buildin_getvariableofinstance: %s is not a variable.\n", script_getstr(st, 2));
+		ShowError("buildin_getinstancevar: %s is not a variable.\n", script_getstr(st, 2));
 		script_reportdata(data);
 		script_pushnil(st);
 		st->state = END;
@@ -25259,7 +25259,7 @@ BUILDIN_FUNC(getvariableofinstance)
 	const char* name = reference_getname(data);
 
 	if (*name != '\'') {
-		ShowError("buildin_getvariableofinstance: Invalid scope. %s is not an instance variable.\n", name);
+		ShowError("buildin_getinstancevar: Invalid scope. %s is not an instance variable.\n", name);
 		script_reportdata(data);
 		script_pushnil(st);
 		st->state = END;
@@ -25269,7 +25269,7 @@ BUILDIN_FUNC(getvariableofinstance)
 	int instance_id = script_getnum(st, 3);
 
 	if (instance_id <= 0) {
-		ShowError("buildin_getvariableofinstance: Invalid instance ID %d.\n", instance_id);
+		ShowError("buildin_getinstancevar: Invalid instance ID %d.\n", instance_id);
 		script_pushnil(st);
 		st->state = END;
 		return SCRIPT_CMD_FAILURE;
@@ -25278,7 +25278,7 @@ BUILDIN_FUNC(getvariableofinstance)
 	std::shared_ptr<s_instance_data> im = util::umap_find(instances, instance_id);
 
 	if (im->state != INSTANCE_BUSY) {
-		ShowError("buildin_getvariableofinstance: Unknown instance ID %d.\n", instance_id);
+		ShowError("buildin_getinstancevar: Unknown instance ID %d.\n", instance_id);
 		script_pushnil(st);
 		st->state = END;
 		return SCRIPT_CMD_FAILURE;
@@ -25291,6 +25291,62 @@ BUILDIN_FUNC(getvariableofinstance)
 	return SCRIPT_CMD_SUCCESS;
 }
 
+/// Sets the value of an instance variable.
+///
+/// setinstancevar(<variable>,<value>,<instance ID>)
+BUILDIN_FUNC(setinstancevar)
+{
+	const char *command = script_getfuncname(st);
+	struct script_data* data = script_getdata(st, 2);
+
+	if (!data_isreference(data)) {
+		ShowError("buildin_%s: %s is not a variable.\n", command, script_getstr(st, 2));
+		script_reportdata(data);
+		script_pushnil(st);
+		st->state = END;
+		return SCRIPT_CMD_FAILURE;
+	}
+
+	const char* name = reference_getname(data);
+
+	if (*name != '\'') {
+		ShowError("buildin_%s: Invalid scope. %s is not an instance variable.\n", command, name);
+		script_reportdata(data);
+		script_pushnil(st);
+		st->state = END;
+		return SCRIPT_CMD_FAILURE;
+	}
+
+	int instance_id = script_getnum(st, 4);
+
+	if (instance_id <= 0) {
+		ShowError("buildin_%s: Invalid instance ID %d.\n", command, instance_id);
+		script_pushnil(st);
+		st->state = END;
+		return SCRIPT_CMD_FAILURE;
+	}
+
+	std::shared_ptr<s_instance_data> im = util::umap_find(instances, instance_id);
+
+	if (im->state != INSTANCE_BUSY) {
+		ShowError("buildin_%s: Unknown instance ID %d.\n", command, instance_id);
+		script_pushnil(st);
+		st->state = END;
+		return SCRIPT_CMD_FAILURE;
+	}
+
+	script_pushcopy(st, 2);
+
+	struct map_session_data* sd = nullptr;
+
+	if( is_string_variable(name) )
+		set_reg_str( st, sd, reference_getuid(data), name, script_getstr( st, 3 ), &im->regs );
+	else
+		set_reg_num( st, sd, reference_getuid(data), name, script_getnum64( st, 3 ), &im->regs );
+
+	return SCRIPT_CMD_SUCCESS;
+}
+
 /*
   convertpcinfo(<char_id>,<type>)
   convertpcinfo(<account_id>,<type>)
@@ -26124,7 +26180,8 @@ struct script_function buildin_func[] = {
 	BUILDIN_DEF(camerainfo,"iii?"),
 
 	BUILDIN_DEF(achievement_condition,"i"),
-	BUILDIN_DEF(getvariableofinstance,"ri"),
+	BUILDIN_DEF(getinstancevar,"ri"),
+	BUILDIN_DEF2_DEPRECATED(getinstancevar, "getvariableofinstance","ri", "2021-12-13"),
 	BUILDIN_DEF(convertpcinfo,"vi"),
 	BUILDIN_DEF(isnpccloaked, "??"),
 
@@ -26135,6 +26192,8 @@ struct script_function buildin_func[] = {
 	BUILDIN_DEF(getenchantgrade, ""),
 
 	BUILDIN_DEF(mob_setidleevent, "is"),
+
+	BUILDIN_DEF(setinstancevar,"rvi"),
 #include "../custom/script_def.inc"
 
 	{NULL,NULL,NULL},