fix 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 533 matching lines @@
 double SkOpCoincidence::TRange(const SkOpPtT* overS, double t,
        const SkOpSegment* coinSeg  SkDEBUGPARAMS(const SkOpPtT* overE)) {
     const SkOpSpanBase* work = overS->span();
     const SkOpPtT* foundStart = nullptr;
     const SkOpPtT* foundEnd = nullptr;
     const SkOpPtT* coinStart = nullptr;
     const SkOpPtT* coinEnd = nullptr;
     do {
         const SkOpPtT* contained = work->contains(coinSeg);
         if (!contained) {
-            if (work->t() >= t) {
-                return 1;
+            if (work->final()) {
+                break;
             }
             continue;
         }
         if (work->t() <= t) {
             coinStart = contained;
             foundStart = work->ptT();
         }
         if (work->t() >= t) {
             coinEnd = contained;
             foundEnd = work->ptT();
             break;
         }
         SkASSERT(work->ptT() != overE);
     } while ((work = work->upCast()->next()));
-    SkASSERT(coinStart);
-    SkASSERT(coinEnd);
+    if (!coinStart || !coinEnd) {
+        return 1;
+    }
     // while overS->fT <=t and overS contains coinSeg
     double denom = foundEnd->fT - foundStart->fT;
     double sRatio = denom ? (t - foundStart->fT) / denom : 1;
     return coinStart->fT + (coinEnd->fT - coinStart->fT) * sRatio;
 }
 
 // return true if span overlaps existing and needs to adjust the coincident list
 bool SkOpCoincidence::checkOverlap(SkCoincidentSpans* check,
         const SkOpSegment* coinSeg, const SkOpSegment* oppSeg,
         double coinTs, double coinTe, double oppTs, double oppTe,
@@ skipping 985 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());
 }