:has() should not have any kind of forgiving behavior

Recent CSS spec updated :has() to not be forgiving. This is to address
JQuery issues. With that said, we do not offer true forgiving anyways,
just comma forgiveness. As CSS will not be allowing forgiveness for
relative selectors, we will not continue supporting it.

docs/src/markdown/about/changelog.md

@@ -1,13 +1,11 @@
 # Changelog
 
-## 2.5
+## 2.4
 
 - **NEW**: Update to support changes related to `:lang()` in the official CSS spec. `:lang("")` should match unspecified
   languages, e.g. `lang=""`, but not `lang=und`.
-
-## 2.4
-
-- **NEW**: `:nth-child()` and `:nth-last-child()` will forgive irregular comma usage.
+- **NEW**: Only `:is()` and `:where()` should allow forgiving selector lists according to latest CSS (as far as Soup
+  Sieve supports "forgiving" which is limited to empty selectors).
 - **NEW**: Formally drop Python 3.6.
 
 ## 2.3.2.post1

soupsieve/__meta__.py

@@ -193,5 +193,5 @@ def parse_version(ver: str) -> Version:
     return Version(major, minor, micro, release, pre, post, dev)
 
 
-__version_info__ = Version(2, 5, 0, "final", post=1)
+__version_info__ = Version(2, 4, 0, "final")
 __version__ = __version_info__._get_canonical()

soupsieve/css_parser.py

@@ -723,7 +723,7 @@ def parse_pseudo_nth(
         if postfix == '_child':
             if m.group('of'):
                 # Parse the rest of `of S`.
-                nth_sel = self.parse_selectors(iselector, m.end(0), FLG_PSEUDO | FLG_OPEN | FLG_FORGIVE)
+                nth_sel = self.parse_selectors(iselector, m.end(0), FLG_PSEUDO | FLG_OPEN)
             else:
                 # Use default `*|*` for `of S`.
                 nth_sel = CSS_NTH_OF_S_DEFAULT
@@ -753,7 +753,7 @@ def parse_pseudo_open(
         if name == ':not':
             flags |= FLG_NOT
         elif name == ':has':
-            flags |= FLG_RELATIVE | FLG_FORGIVE
+            flags |= FLG_RELATIVE
         elif name in (':where', ':is'):
             flags |= FLG_FORGIVE
 
@@ -777,11 +777,6 @@ def parse_has_combinator(
         if not combinator:
             combinator = WS_COMBINATOR
         if combinator == COMMA_COMBINATOR:
-            if not has_selector:
-                # If we've not captured any selector parts, the comma is either at the beginning of the pattern
-                # or following another comma, both of which are unexpected. But shouldn't fail the pseudo-class.
-                sel.no_match = True
-
             sel.rel_type = rel_type
             selectors[-1].relations.append(sel)
             rel_type = ":" + WS_COMBINATOR
@@ -1070,22 +1065,12 @@ def parse_selectors(
                 selectors.append(sel)
 
         # Forgive empty slots in pseudo-classes that have lists (and are forgiving)
-        elif is_forgive:
-            if is_relative:
-                # Handle relative selectors pseudo-classes with empty slots like `:has()`
-                if selectors and selectors[-1].rel_type is None and rel_type == ': ':
-                    sel.rel_type = rel_type
-                    sel.no_match = True
-                    selectors[-1].relations.append(sel)
-                    has_selector = True
-            else:
-                # Handle normal pseudo-classes with empty slots
-                if not selectors or not relations:
-                    # Others like `:is()` etc.
-                    sel.no_match = True
-                    del relations[:]
-                    selectors.append(sel)
-                    has_selector = True
+        elif is_forgive and (not selectors or not relations):
+            # Handle normal pseudo-classes with empty slots like `:is()` etc.
+            sel.no_match = True
+            del relations[:]
+            selectors.append(sel)
+            has_selector = True
 
         if not has_selector:
             # We will always need to finish a selector when `:has()` is used as it leads with combining.

tests/test_level4/test_has.py

@@ -129,45 +129,20 @@ def test_has_nested_pseudo(self):
             flags=util.HTML
         )
 
-    def test_has_empty(self):
-        """Test has with empty slot due to multiple commas."""
+    def test_has_no_match(self):
+        """Test has with a non-matching selector."""
 
         self.assert_selector(
             self.MARKUP2,
-            'div:has()',
+            'div:has(:paused)',
             [],
             flags=util.HTML
         )
 
-    def test_has_multi_commas(self):
+    def test_has_empty(self):
         """Test has with empty slot due to multiple commas."""
 
-        self.assert_selector(
-            self.MARKUP2,
-            'div:has(> .bbbb, .ffff, , .jjjj)',
-            ['0', '4', '8'],
-            flags=util.HTML
-        )
-
-    def test_has_leading_commas(self):
-        """Test has with empty slot due to leading commas."""
-
-        self.assert_selector(
-            self.MARKUP2,
-            'div:has(, > .bbbb, .ffff, .jjjj)',
-            ['0', '4', '8'],
-            flags=util.HTML
-        )
-
-    def test_has_trailing_commas(self):
-        """Test has with empty slot due to trailing commas."""
-
-        self.assert_selector(
-            self.MARKUP2,
-            'div:has(> .bbbb, .ffff, .jjjj, )',
-            ['0', '4', '8'],
-            flags=util.HTML
-        )
+        self.assert_raises('div:has()', SelectorSyntaxError)
 
     def test_invalid_incomplete_has(self):
         """Test `:has()` fails with just a combinator."""

tests/test_level4/test_nth_child.py

@@ -46,13 +46,3 @@ def test_nth_child_of_s_complex(self):
             ['2', '6', '10'],
             flags=util.HTML
         )
-
-    def test_nth_child_forgive(self):
-        """Test that `nth` child forgives bad commas."""
-
-        self.assert_selector(
-            self.MARKUP,
-            ":nth-child(2n + 1 OF p.test,, span.test,)",
-            ['2', '6', '10'],
-            flags=util.HTML
-        )

tests/test_level4/test_nth_last_child.py

@@ -31,30 +31,3 @@ def test_nth_child_of_s_complex(self):
             ['1', '3', '5', '7', '9', '11'],
             flags=util.HTML
         )
-
-    def test_nth_last_child_forgive(self):
-        """Test `nth` last child forgives irregular commas."""
-
-        markup = """
-        <body>
-        <p id="0"></p>
-        <p id="1"></p>
-        <span id="2"></span>
-        <span id="3"></span>
-        <span id="4"></span>
-        <span id="5"></span>
-        <span id="6"></span>
-        <p id="7"></p>
-        <p id="8"></p>
-        <p id="9"></p>
-        <p id="10"></p>
-        <span id="11"></span>
-        </body>
-        """
-
-        self.assert_selector(
-            markup,
-            ":nth-last-child(2n + 1 of ,p[id],, span[id],)",
-            ['1', '3', '5', '7', '9', '11'],
-            flags=util.HTML
-        )