Revert "Don't skip over spacing marks when kerning (#720)"

Lib/ufo2ft/featureWriters/kernFeatureWriter.py

@@ -361,25 +361,7 @@ def _makePairPosRule(self, pair, side1Classes, side2Classes, rtl=False):
     def _makeKerningLookup(self, name, ignoreMarks=True):
         lookup = ast.LookupBlock(name)
         if ignoreMarks and self.options.ignoreMarks:
-            # We only want to filter the spacing marks
-            marks = self.context.gdefClasses.mark
-            spacing = []
-            if marks:
-                spacing = [mark for mark in marks if self.context.font[mark].width != 0]
-            if not spacing:
-                # Simple case, there are no spacing ("Spacing Combining") marks,
-                # do what we've always done.
-                lookup.statements.append(ast.makeLookupFlag("IgnoreMarks"))
-            else:
-                # We want spacing marks to block kerns.
-                className = "MFS_%s" % name
-                filteringClass = ast.makeGlyphClassDefinitions(
-                    {className: spacing}, feaFile=self.context.feaFile
-                )[className]
-                lookup.statements.append(filteringClass)
-                lookup.statements.append(
-                    ast.makeLookupFlag(markFilteringSet=filteringClass)
-                )
+            lookup.statements.append(ast.makeLookupFlag("IgnoreMarks"))
         return lookup
 
     def knownScriptsPerCodepoint(self, uv: int) -> set[str]:

tests/featureWriters/kernFeatureWriter_test.py

@@ -1,5 +1,4 @@
 import logging
-import os
 from textwrap import dedent
 
 import pytest
@@ -1260,39 +1259,6 @@ def test_quantize(self, FontClass):
             """
         )
 
-    def test_skip_spacing_marks(self, FontClass):
-        dirname = os.path.dirname(os.path.dirname(__file__))
-        fontPath = os.path.join(dirname, "data", "SpacingCombiningTest-Regular.ufo")
-        testufo = FontClass(fontPath)
-        generated = self.writeFeatures(testufo)
-        assert dedent(str(generated)) == dedent(
-            """\
-            lookup kern_Deva {
-                @MFS_kern_Deva = [highspacingdot-deva];
-                lookupflag UseMarkFilteringSet @MFS_kern_Deva;
-                pos ka-deva ra-deva -250;
-                pos ra-deva ka-deva -250;
-            } kern_Deva;
-
-            lookup kern_Deva_marks {
-                pos highspacingdot-deva ka-deva -200;
-                pos ka-deva highspacingdot-deva -150;
-            } kern_Deva_marks;
-
-            feature dist {
-                script dev2;
-                language dflt;
-                lookup kern_Deva;
-                lookup kern_Deva_marks;
-
-                script deva;
-                language dflt;
-                lookup kern_Deva;
-                lookup kern_Deva_marks;
-            } dist;
-            """
-        )
-
 
 def test_kern_split_multi_glyph_class(FontClass):
     glyphs = {