Problems with color components

This glyphs file: BadColor.glyphs.gz has two masters, each with two color layers. I would expect these layers to be exported as ".color0" and ".color1". However, the names of some (not all!) component glyphs used in these masters are incorrect:

$ glyphs2ufo BadColor.glyphs
$ cat BadColor-Thin.ufo/glyphs.color.1/A_acute.glif
<?xml version='1.0' encoding='UTF-8'?>
<glyph name="Aacute" format="2">
  <advance width="500"/>
  <unicode hex="00C1"/>
  <anchor x="685" y="10" name="ogonek"/>
  <anchor x="355" y="708" name="top"/>
  <outline>
    <component base="A.color1"/>
    <component base="acutecomb.color2" xOffset="370" yOffset="208"/>
  </outline>

There is no color2, so the font does not compile.

the issue must be somewhere here:

glyphsLib/Lib/glyphsLib/builder/components.py

Lines 50 to 69 in ed02363

    
           for index, component in enumerate(layer.components): 
        
               component_name = component.name 
        
               if layer._is_color_palette_layer(): 
        
                   # Glyphs handles components for color layers in a special way. If 
        
                   # the component glyph has color layers of its own, the component 
        
                   # use the first color layer with the same color index, otherwise it 
        
                   # fallback to the default layer. We try to do that here as well. 
        
                   font = layer.parent.parent 
        
                   component_glyph = font.glyphs[component_name] 
        
                   color_layers = [ 
        
                       l for l in component_glyph.layers if l._is_color_palette_layer() 
        
                   ] 
        
                   for i, l in enumerate(color_layers): 
        
                       if l._color_palette_index() == layer._color_palette_index(): 
        
                           if l.layerId != l.associatedMasterId: 
        
                               # If it is not a master layer, we rename it in 
        
                               # _to_ufo_color_palette_layers(), so we reference the 
        
                               # same name here. 
        
                               component_name += f".color{i}" 
        
                           break

Yep, that looks suspicious. I will try to fix.

thanks. I tried to understand what was going on but failed so far, happy to pass it to you

Fixed by #974

	for index, component in enumerate(layer.components):
	component_name = component.name
	if layer._is_color_palette_layer():
	# Glyphs handles components for color layers in a special way. If
	# the component glyph has color layers of its own, the component
	# use the first color layer with the same color index, otherwise it
	# fallback to the default layer. We try to do that here as well.
	font = layer.parent.parent
	component_glyph = font.glyphs[component_name]
	color_layers = [
	l for l in component_glyph.layers if l._is_color_palette_layer()
	]
	for i, l in enumerate(color_layers):
	if l._color_palette_index() == layer._color_palette_index():
	if l.layerId != l.associatedMasterId:
	# If it is not a master layer, we rename it in
	# _to_ufo_color_palette_layers(), so we reference the
	# same name here.
	component_name += f".color{i}"
	break