Bug 1774791 - Fix grid shorthand parsing to not incorrectly ignore the last token in one case. r=dholbert

Differential Revision: https://phabricator.services.mozilla.com/D149666

servo/components/style/properties/shorthands/position.mako.rs

@@ -600,7 +600,7 @@
             temp_rows = rows;
             input.expect_delim('/')?;
             flow = parse_auto_flow(input, false)?;
-            auto_cols = grid_auto_columns::parse(context, input).unwrap_or_default();
+            auto_cols = input.try_parse(|i| grid_auto_columns::parse(context, i)).unwrap_or_default();
         } else {
             flow = parse_auto_flow(input, true)?;
             auto_rows = input.try_parse(|i| grid_auto_rows::parse(context, i)).unwrap_or_default();

testing/web-platform/tests/css/css-grid/parsing/grid-shorthand-invalid.html

@@ -46,6 +46,7 @@ test_invalid_value("grid", 'auto-flow 100px');
 test_invalid_value("grid", 'auto-flow / auto-flow');
 test_invalid_value("grid", 'auto-flow 1fr / auto-flow 1fr');
 test_invalid_value("grid", 'dense auto-flow / dense auto-flow');
+test_invalid_value("grid", 'auto / auto-flow foo()');
 // FIXME: add more values to test full syntax
 
 </script>