Allow uppercase identifiers for grid lines

Related to #2383.

Author: liZe

tests/css/test_validation.py

@@ -964,12 +964,12 @@ def test_grid_template_areas_invalid(rule):
 @pytest.mark.parametrize('rule, value', (
     ('auto', 'auto'),
     ('4', (None, 4, None)),
-    ('C', (None, None, 'c')),
+    ('C', (None, None, 'C')),
     ('4 c', (None, 4, 'c')),
     ('col -4', (None, -4, 'col')),
     ('span c 4', ('span', 4, 'c')),
     ('span 4 c', ('span', 4, 'c')),
-    ('4 span c', ('span', 4, 'c')),
+    ('4 span C', ('span', 4, 'C')),
     ('super 4 span', ('span', 4, 'super')),
 ))
 def test_grid_line(rule, value):

weasyprint/css/validation/properties.py

@@ -1626,7 +1626,7 @@ def grid_line(tokens):
             if keyword == 'auto':
                 return keyword
             elif keyword != 'span':
-                return (None, None, keyword)
+                return (None, None, token.value)
         elif token.type == 'number' and token.is_integer and token.value:
             return (None, token.int_value, None)
         return
@@ -1640,7 +1640,7 @@ def grid_line(tokens):
                     span = 'span'
                     continue
             elif keyword and ident is None:
-                ident = keyword
+                ident = token.value
                 continue
         elif token.type == 'number' and token.is_integer and token.value:
             if number is None: