fix pathops fuzz

src/pathops/SkOpSegment.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkOpSegment_DEFINE
 #define SkOpSegment_DEFINE
 
 #include "SkOpAngle.h"
@@ skipping 56 matching lines @@
     SkOpAngle* addEndSpan() {
         SkOpAngle* angle = SkOpTAllocator<SkOpAngle>::Allocate(this->globalState()->allocator());
         angle->set(&fTail, fTail.prev());
         fTail.setFromAngle(angle);
         return angle;
     }
 
     bool addExpanded(double newT, const SkOpSpanBase* test, bool* startOver);
 
     SkOpSegment* addLine(SkPoint pts[2], SkOpContour* parent) {
+        SkASSERT(pts[0] != pts[1]);
         init(pts, 1, parent, SkPath::kLine_Verb);
         fBounds.set(pts, 2);
         return this;
     }
 
     SkOpPtT* addMissing(double t, SkOpSegment* opp, bool* allExist);
 
     SkOpAngle* addStartSpan() {
         SkOpAngle* angle = SkOpTAllocator<SkOpAngle>::Allocate(this->globalState()->allocator());
         angle->set(&fHead, fHead.next());
@@ skipping 352 matching lines @@
     int fDoneCount;  // number of processed spans (zero initially)
     SkPath::Verb fVerb;
     bool fVisited;  // used by missing coincidence check
 #if DEBUG_COINCIDENCE
     mutable bool fDebugVisited;  // used by debug missing coincidence check
 #endif
     SkDEBUGCODE(int fID);
 };
 
 #endif