Invalid get index of type StringName on base Dictionary when key is an empty StringName

[maniacalipsis]

Godot version

4.0.3 stable

System information

Kubuntu 22.04

Issue description

I have a dictionary with string keys, and one of the keys is "" (empty string). To get values from dictionary by the key, the StringName parameter is used. So all works fine unless the key is an empty StringName.
Context: dictionary stores some data about input actions, that are type of StringName (and certain Input and InputEvent methods expects StringName arguments), that's why this type is prefered rather than String. And one of the dictionary elements is kinda nil-element, used to eliminate if _dict.has(key) checks.

Steps to reproduce

1. Make *.gd script
2. Add a Dictionary variable, e.g. var _dict:={}
3. Add some value with empty key _dict[&""]=someval or _dict[""]=someval
4. Try to get this value like print(_dict[&""])

Minimal reproduction project

Example declaration:

class_name Something extends Node

var _dict:={&"":"--emptyness--",&"a":"A"}

func get_val_by_strname(key:StringName):
   return _dict[key]

func get_val_by_strname_converted(key:StringName):
   return _dict[key as String]

func get_val_by_str(key:String):
   return _dict[key]

Example usage:

print(Something.get_val_by_str("A"))  #Will print "A".
print(Something.get_val_by_strname_converted(&"A"))  #Will print "A".
print(Something.get_val_by_strname(&"A"))  #Will print "A".

print(Something.get_val_by_str(""))  #Will print "--emptyness--".
print(Something.get_val_by_strname_converted(&""))  #Will print "--emptyness--".
print(Something.get_val_by_strname(&""))  #Will throw an error "Invalid get index of type StringName on base Dictionary".

[AThousandShips]

This seems to be due to that this lookup uses the internal getptr function which doesn't do the conversion from StringName to String, will investigate further

Be aware however that Dictionary does not store StringName internally but stores as String

• Might be fixed by StringName Dictionary keys #70096 (haven't tested)

[tech6hutch]

I just encountered this too (v4.0.3.stable.official [5222a99]). Here's a shorter reproduction:

var dict := {}
dict[&""] = 0
dict[&""] += 1