break ambiguous angle sorting loop

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 217 matching lines @@
 }
 
 static void move_nearby(SkOpContourHead* contourList  DEBUG_COIN_DECLARE_PARAMS()) {
     DEBUG_STATIC_SET_PHASE(contourList);
     SkOpContour* contour = contourList;
     do {
         contour->moveNearby();
     } while ((contour = contour->next()));
 }
 
-static void sort_angles(SkOpContourHead* contourList) {
+static bool sort_angles(SkOpContourHead* contourList) {
     SkOpContour* contour = contourList;
     do {
-        contour->sortAngles();
+        if (!contour->sortAngles()) {
+            return false;
+        }
     } while ((contour = contour->next()));
+    return true;
 }
 
 bool HandleCoincidence(SkOpContourHead* contourList, SkOpCoincidence* coincidence) {
     SkOpGlobalState* globalState = contourList->globalState();
     // match up points within the coincident runs
     if (!coincidence->addExpanded(DEBUG_PHASE_ONLY_PARAMS(kIntersecting))) {
         return false;
     }
     // combine t values when multiple intersections occur on some segments but not others
     if (!move_multiples(contourList  DEBUG_PHASE_PARAMS(kWalking))) {
@@ skipping 67 matching lines @@
         // are different, construct a new pair to resolve their mutual span
         if (!pairs->findOverlaps(&overlaps  DEBUG_ITER_PARAMS(SAFETY_COUNT - safetyHatch))) {
             return false;
         }
         if (!--safetyHatch) {
             SkASSERT(globalState->debugSkipAssert());
             return false;
         }
     } while (!overlaps.isEmpty());
     calc_angles(contourList  DEBUG_COIN_PARAMS());
-    sort_angles(contourList);
+    if (!sort_angles(contourList)) {
+        return false;
+    }
 #if DEBUG_COINCIDENCE_VERBOSE
     coincidence->debugShowCoincidence();
 #endif
 #if DEBUG_COINCIDENCE
     coincidence->debugValidate();
 #endif
     SkPathOpsDebug::ShowActiveSpans(contourList);
     return true;
 }