fix coincident fuzzer

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 92 matching lines @@
                     return false;
                 }
                 double oStartPart = (oTest->t() - oStartPtT->fT) / oStartRange;
                 if (startPart == oStartPart) {
                     return false;
                 }
                 SkOpPtT* newPt;
                 if (startPart < oStartPart) {
                     double newT = oStartPtT->fT + oStartRange * startPart;
                     newPt = oStart->segment()->addT(newT, SkOpSegment::kAllowAlias, allocator);
+                    if (!newPt) {
+                        return false;
+                    }
                     newPt->fPt = test->pt();
                     test->ptT()->addOpp(newPt);
                 } else {
                     double newT = startPtT->fT + startRange * oStartPart;
                     newPt = start->segment()->addT(newT, SkOpSegment::kAllowAlias, allocator);
+                    if (!newPt) {
+                        return false;
+                    }
                     newPt->fPt = oTest->pt();
                     oTest->ptT()->addOpp(newPt);
                 }
                 // start over
                 test = start;
                 oTest = oStart;
             }
             if (test != end) {
                 test = test->upCast()->next();
             }
@@ skipping 539 matching lines @@
     *overS = SkTMax(SkTMin(coin1s->fT, coin1e->fT), SkTMin(coin2s->fT, coin2e->fT));
     *overE = SkTMin(SkTMax(coin1s->fT, coin1e->fT), SkTMax(coin2s->fT, coin2e->fT));
     return *overS < *overE;
 }
 
 bool SkOpCoincidence::testForCoincidence(const SkCoincidentSpans* outer, const SkOpPtT* testS,
         const SkOpPtT* testE) const {
     return testS->segment()->testForCoincidence(testS, testE, testS->span(),
             testE->span(), outer->fCoinPtTStart->segment(), 120000);  // FIXME: replace with tuned
 }