split tight quads and cubics

src/pathops/SkOpCoincidence.cpp

Index: src/pathops/SkOpCoincidence.cpp
diff --git a/src/pathops/SkOpCoincidence.cpp b/src/pathops/SkOpCoincidence.cpp
index 446f34cb26abb0fff8991309e5fc2c5e885ec6a7..8f9c5be3fcd8cee28f6c2bf7824fbb592e011d7f 100755
--- a/src/pathops/SkOpCoincidence.cpp
+++ b/src/pathops/SkOpCoincidence.cpp
@@ -334,6 +334,9 @@ bool SkOpCoincidence::addEndMovedSpans(const SkOpSpan* base, const SkOpSpanBase*
             }
             SkOpSegment* writableSeg = const_cast<SkOpSegment*>(testSeg);
             SkOpPtT* oppStart = writableSeg->addT(t);
+            if (oppStart == testPtT) {
+                continue;
+            }
             SkOpSpan* writableBase = const_cast<SkOpSpan*>(base);
             oppStart->span()->addOpp(writableBase);
             if (oppStart->deleted()) {