Accept valueless Gerber attributes

src/gerbonara/rs274x.py

@@ -1081,7 +1081,7 @@ class GerberParser:
 
         else:
             target = {'TF': self.file_attrs, 'TO': self.graphics_state.object_attrs, 'TA': self.aperture_attrs}[match['type']]
-            target[match['name']] = tuple(match['value'].split(','))
+            target[match['name']] = tuple(match['value'].split(',')) if match['value'] else ()
 
             if 'EAGLE' in self.file_attrs.get('.GenerationSoftware', []) or match['eagle_garbage']:
                 self.generator_hints.append('eagle')

tests/test_rs274x.py

@@ -29,6 +29,20 @@ from gerbonara.cam import FileSettings
 from .image_support import *
 from .utils import *
 
+def test_attribute_without_value_is_stored_as_empty_tuple():
+    data = '\n'.join([
+        '%FSLAX24Y24*%',
+        '%MOIN*%',
+        '%TF.FlagLike*%',
+        '%ADD10C,0.0100*%',
+        'D10*',
+        'X0Y0D03*',
+        'M02*',
+    ])
+
+    parsed = GerberFile.from_string(data)
+    assert parsed.file_attrs['.FlagLike'] == ()
+
 # Note: We have a testcase for gitlab issues #10/#11 in therm_1.gbr, but we can't test for that at this time because
 # gerbv chokes on that gerber file and does'nt produce any output.
 REFERENCE_FILES = [ l.strip() for l in '''