fix fuzz bugs

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 407 matching lines @@
     do {
         const SkOpPtT* startPtT = coin->coinPtTStart();
         const SkOpPtT* oStartPtT = coin->oppPtTStart();
         SkASSERT(startPtT->contains(oStartPtT));
         SkASSERT(coin->coinPtTEnd()->contains(coin->oppPtTEnd()));
         const SkOpSpanBase* start = startPtT->span();
         const SkOpSpanBase* oStart = oStartPtT->span();
         const SkOpSpanBase* end = coin->coinPtTEnd()->span();
         const SkOpSpanBase* oEnd = coin->oppPtTEnd()->span();
         FAIL_IF(oEnd->deleted());
+        FAIL_IF(!start->upCastable());
         const SkOpSpanBase* test = start->upCast()->next();
         const SkOpSpanBase* oTest = coin->flipped() ? oStart->prev() : oStart->upCast()->next();
         if (!oTest) {
             return false;
         }
         while (test != end || oTest != oEnd) {
             if (!test->ptT()->contains(oStart->segment())
                     || !oTest->ptT()->contains(start->segment())) {
                 // use t ranges to guess which one is missing
                 double startRange = coin->coinPtTEnd()->fT - startPtT->fT;
                 FAIL_IF(!startRange);
                 double startPart = (test->t() - startPtT->fT) / startRange;
                 double oStartRange = coin->oppPtTEnd()->fT - oStartPtT->fT;
                 FAIL_IF(!oStartRange);
                 double oStartPart = (oTest->t() - oStartPtT->fT) / oStartRange;
                 FAIL_IF(startPart == oStartPart);
                 bool startOver = false;
                 bool success = startPart < oStartPart
                         ? oStart->segment()->addExpanded(
                                 oStartPtT->fT + oStartRange * startPart, test, &startOver)
                         : start->segment()->addExpanded(
                                 startPtT->fT + startRange * oStartPart, oTest, &startOver);
                 if (!success) {
-                    SkASSERT(fGlobalState->debugSkipAssert());
+                    SkOPASSERT(false);
                     return false;
                 }
                 if (startOver) {
                     test = start;
                     oTest = oStart;
                 }
             }
             if (test != end) {
                 test = test->upCast()->next();
             }
@@ skipping 986 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());
 }