Parameter "fd" is null when switching fonts in TextEdit

[bitwes]

Tested versions

• Reproducible in: 4.5 beta 6 official, 4.5 beta 7 official
• Not Reproducible in: 4.4.1 official

System information

MacOS Sequoia 15.6.1 (24G90), Windows 10

Issue description

If you

• load a font dynamically
• use it to override a theme font on a Text Edit
• do not keep a reference to it,
• remove the font override

Godot will generate a number of 'Parameter "fd" is null' errors proportional to the number of characters in the TextEdit. If there are no characters in the TextEdit no errors are generated.

E 0:00:00:334   main.gd:23 @ swap_font(): Parameter "fd" is null.
  <C++ Source>  modules/text_server_adv/text_server_adv.cpp:2844 @ _font_get_ascent()
  <Stack Trace> main.gd:23 @ swap_font()
                main.gd:12 @ _ready()

You can workaround this by keeping a reference to the font yourself. This might be the intended behavior but it did not work this way in Godot 4.4.1 so I thought I'd report it.

Steps to reproduce

Here's the source for the project below.

extends Node2D

@onready var text_edit = $TextEdit

var keep_reference = false
var _font_ref = null

func _ready():
	text_edit.text = "hello world"
	
	swap_font('custom')
	swap_font('default')
	

func swap_font(which):
	if(which == 'custom'):
		var dynamic_font = FontFile.new()
		dynamic_font.load_dynamic_font("res://CourierPrime-Regular.ttf")
		text_edit.add_theme_font_override('font', dynamic_font)
		if(keep_reference):
			_font_ref = dynamic_font
	else:
		text_edit.remove_theme_font_override('font')

If you open the project and run the main scene it will generate 44 errors.

• You can change the text and rerun to see how the errors scale with characters in the TextEdit.
• If you change the text to an empty string then no errors are generated.
• If you set keep_reference to true and have text in the TextEdit then no errors are generated. This is the workaround/what-you-should-actually-do mentioned above.

Minimal reproduction project (MRP)

fd_is_null.zip

[AThousandShips]

Related:

• Error Parameter "fd" is null when changing language in-game #106597

[bruvzg]

#106597

Probably not, it seems to be a new issue caused by addition of embedded color indicators in the code editor.