[FIX] web_editor: properly convert fonts to images

export_icon_to_png sometimes failed because PIL's getbbox returned None.
This fixes it by not using a default color of (0, 0, 0, 0) when creating
the image but using the actual color of the image instead.
Also, the size of the image was wrong because of using the default size
when width and height are defined.

task-2761098

closes odoo/odoo#84565

Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>

addons/web_editor/controllers/main.py

@@ -57,6 +57,7 @@ class Web_Editor(http.Controller):
 
             :returns PNG image converted from given font
         """
+        size = max(width, height, 1) if width else size
         width = width or size
         height = height or size
         # Make sure we have at least size=1
@@ -75,7 +76,7 @@ class Web_Editor(http.Controller):
             bg = ','.join(bg.split(',')[:-1])+')'
 
         # Determine the dimensions of the icon
-        image = Image.new("RGBA", (width, height), color=(0, 0, 0, 0))
+        image = Image.new("RGBA", (width, height), color)
         draw = ImageDraw.Draw(image)
 
         boxw, boxh = draw.textsize(icon, font=font_obj)