split tight quads and cubics

src/pathops/SkOpCoincidence.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkOpCoincidence.h"
 #include "SkOpSegment.h"
 #include "SkPathOpsTSect.h"
 
@@ skipping 316 matching lines @@
             double t = i[0][index];
             if (!between(0, t, 1)) {
                 continue;
             }
             SkDPoint oppPt = i.pt(index);
             if (!oppPt.approximatelyEqual(pt)) {
                 continue;
             }
             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()) {
                 continue;
             }
             SkOpSegment* coinSeg = base->segment();
             SkOpSegment* oppSeg = oppStart->segment();
             double coinTs, coinTe, oppTs, oppTe;
             if (Ordered(coinSeg, oppSeg)) {
                 coinTs = base->t();
@@ skipping 1256 matching lines @@
             this->release(fHead, coin);
         }
     } while ((coin = coin->next()));
 }
 
 bool SkOpCoincidence::testForCoincidence(const SkCoincidentSpans* outer, const SkOpPtT* testS,
         const SkOpPtT* testE) const {
     return testS->segment()->testForCoincidence(testS, testE, testS->span(),
             testE->span(), outer->coinPtTStart()->segment());
 }