fix path ops fuzz bug

src/pathops/SkPathOpsCommon.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkAddIntersections.h"
 #include "SkOpCoincidence.h"
 #include "SkOpEdgeBuilder.h"
 #include "SkPathOpsCommon.h"
@@ skipping 407 matching lines @@
 static bool missingCoincidence(SkOpContourHead* contourList,
         SkOpCoincidence* coincidence, SkChunkAlloc* allocator) {
     SkOpContour* contour = contourList;
     bool result = false;
     do {
         result |= contour->missingCoincidence(coincidence, allocator);
     } while ((contour = contour->next()));
     return result;
 }
 
-static void moveMultiples(SkOpContourHead* contourList) {
+static bool moveMultiples(SkOpContourHead* contourList) {
     SkOpContour* contour = contourList;
     do {
-        contour->moveMultiples();
+        if (!contour->moveMultiples()) {
+            return false;
+        }
     } while ((contour = contour->next()));
+    return true;
 }
 
 static void moveNearby(SkOpContourHead* contourList) {
     SkOpContour* contour = contourList;
     do {
         contour->moveNearby();
     } while ((contour = contour->next()));
 }
 
 static void sortAngles(SkOpContourHead* contourList) {
     SkOpContour* contour = contourList;
     do {
         contour->sortAngles();
     } while ((contour = contour->next()));
 }
 
 bool HandleCoincidence(SkOpContourHead* contourList, SkOpCoincidence* coincidence,
         SkChunkAlloc* allocator) {
     SkOpGlobalState* globalState = contourList->globalState();
     // combine t values when multiple intersections occur on some segments but not others
     DEBUG_COINCIDENCE_HEALTH(contourList, "start");
-    moveMultiples(contourList);
+    if (!moveMultiples(contourList)) {
+        return false;
+    }
     DEBUG_COINCIDENCE_HEALTH(contourList, "moveMultiples");
     findCollapsed(contourList);
     DEBUG_COINCIDENCE_HEALTH(contourList, "findCollapsed");
     // move t values and points together to eliminate small/tiny gaps
     moveNearby(contourList);
     DEBUG_COINCIDENCE_HEALTH(contourList, "moveNearby");
     align(contourList);  // give all span members common values
     DEBUG_COINCIDENCE_HEALTH(contourList, "align");
     coincidence->fixAligned();  // aligning may have marked a coincidence pt-t deleted
     DEBUG_COINCIDENCE_HEALTH(contourList, "fixAligned");
@@ skipping 57 matching lines @@
         if (!coincidence->apply()) {
             return false;
         }
     }
 #if DEBUG_ACTIVE_SPANS
     coincidence->debugShowCoincidence();
     DebugShowActiveSpans(contourList);
 #endif
     return true;
 }