fix ERROR on check/unreachable_glyphs

Be sure we have a LayerList before attempting to access it.

com.google.fonts/check/unreachable_glyphs
On Shaping profile.

(issue #4786)

CHANGELOG.md

@@ -17,6 +17,9 @@ A more detailed list of changes is available in the corresponding milestones for
 #### On the Universal profile
   - **[com.google.fonts/check/gsub/smallcaps_before_ligatures]:** Skip check if font lacks GSUB table or font is missing either liga or smcp features. (PR #4787)
 
+#### On the Shaping profile
+  - **[com.google.fonts/check/unreachable_glyphs]:** Fix ERROR by being sure that we have a LayerList before attempting to access it. (issue #4786)
+
 
 ## 0.12.8 (2024-Jul-05)
 ### Noteworthy code-changes

Lib/fontbakery/checks/universal/glyphset.py

@@ -237,9 +237,10 @@ def remove_lookup_outputs(all_glyphs, lookup):
                 if hasattr(paint_record.Paint, "Glyph"):
                     all_glyphs.discard(paint_record.Paint.Glyph)
 
-            for paint in ttFont["COLR"].table.LayerList.Paint:
-                if hasattr(paint, "Glyph"):
-                    all_glyphs.discard(paint.Glyph)
+            if ttFont["COLR"].table.LayerList:
+                for paint in ttFont["COLR"].table.LayerList.Paint:
+                    if hasattr(paint, "Glyph"):
+                        all_glyphs.discard(paint.Glyph)
 
     if "GSUB" in ttFont and ttFont["GSUB"].table.LookupList:
         lookups = ttFont["GSUB"].table.LookupList.Lookup