1 files changed, 43 insertions, 2 deletions
diff --git a/Tests/varLib/instancer/instancer_test.py b/Tests/varLib/instancer/instancer_test.py
index cb7e8547..bb2d1758 100644
--- a/Tests/varLib/instancer/instancer_test.py
+++ b/Tests/varLib/instancer/instancer_test.py
@@ -1,5 +1,5 @@
-from fontTools.misc.py23 import Tag
 from fontTools.misc.fixedTools import floatToFixedToFloat
+from fontTools.misc.textTools import Tag
 from fontTools import ttLib
 from fontTools import designspaceLib
 from fontTools.feaLib.builder import addOpenTypeFeaturesFromString
@@ -936,6 +936,30 @@ class InstantiateOTLTest(object):
         assert not hasattr(valueRec1, "XAdvDevice")
         assert valueRec1.XAdvance == v2
 
+    def test_GPOS_ValueRecord_XAdvDevice_wtihout_XAdvance(self):
+        # Test VF contains a PairPos adjustment in which the default instance
+        # has no XAdvance but there are deltas in XAdvDevice (VariationIndex).
+        vf = ttLib.TTFont()
+        vf.importXML(os.path.join(TESTDATA, "PartialInstancerTest4-VF.ttx"))
+        pairPos = vf["GPOS"].table.LookupList.Lookup[0].SubTable[0]
+        assert pairPos.ValueFormat1 == 0x40
+        valueRec1 = pairPos.PairSet[0].PairValueRecord[0].Value1
+        assert not hasattr(valueRec1, "XAdvance")
+        assert valueRec1.XAdvDevice.DeltaFormat == 0x8000
+        outer = valueRec1.XAdvDevice.StartSize
+        inner = valueRec1.XAdvDevice.EndSize
+        assert vf["GDEF"].table.VarStore.VarData[outer].Item[inner] == [-50]
+
+        # check that MutatorMerger for ValueRecord doesn't raise AttributeError
+        # when XAdvDevice is present but there's no corresponding XAdvance.
+        instancer.instantiateOTL(vf, {"wght": 0.5})
+
+        pairPos = vf["GPOS"].table.LookupList.Lookup[0].SubTable[0]
+        assert pairPos.ValueFormat1 == 0x4
+        valueRec1 = pairPos.PairSet[0].PairValueRecord[0].Value1
+        assert not hasattr(valueRec1, "XAdvDevice")
+        assert valueRec1.XAdvance == -25
+
 
 class InstantiateAvarTest(object):
     @pytest.mark.parametrize("location", [{"wght": 0.0}, {"wdth": 0.0}])
@@ -1387,7 +1411,7 @@ def _dump_ttx(ttFont):
     tmp.seek(0)
     ttFont2 = ttLib.TTFont(tmp, recalcBBoxes=False, recalcTimestamp=False)
     s = StringIO()
-    ttFont2.saveXML(s, newlinestr="\n")
+    ttFont2.saveXML(s)
     return _strip_ttLibVersion(s.getvalue())
 
 
@@ -1452,6 +1476,23 @@ class InstantiateVariableFontTest(object):
 
         assert _dump_ttx(instance) == expected
 
+    def test_singlepos(self):
+        varfont = ttLib.TTFont(recalcTimestamp=False)
+        varfont.importXML(os.path.join(TESTDATA, "SinglePos.ttx"))
+
+        location = {"wght": 280, "opsz": 18}
+
+        instance = instancer.instantiateVariableFont(
+            varfont, location,
+        )
+
+        expected = _get_expected_instance_ttx(
+            "SinglePos", *location.values()
+        )
+
+        assert _dump_ttx(instance) == expected
+
+
 
 def _conditionSetAsDict(conditionSet, axisOrder):
     result = {}