pathops coincidence and security rewrite

src/pathops/SkOpBuilder.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkMatrix.h"
 #include "SkOpEdgeBuilder.h"
 #include "SkPathPriv.h"
@@ skipping 26 matching lines @@
         if (dir != SkPathPriv::kCCW_FirstDirection) {
             SkPath temp;
             temp.reverseAddPath(*path);
             *path = temp;
         }
         path->setFillType(fillType);
         return true;
     }
     SkChunkAlloc allocator(4096);
     SkOpContourHead contourHead;
-    SkOpGlobalState globalState(nullptr, &contourHead  SkDEBUGPARAMS(false)
+    SkOpGlobalState globalState(&contourHead, &allocator  SkDEBUGPARAMS(false)
             SkDEBUGPARAMS(nullptr));
-    SkOpEdgeBuilder builder(*path, &contourHead, &allocator, &globalState);
-    builder.finish(&allocator);
-    if (!contourHead.next()) {
-        return false;
-    }
+    SkOpEdgeBuilder builder(*path, &contourHead, &globalState);
+    builder.finish();
+    SkASSERT(contourHead.next());
     contourHead.resetReverse();
     bool writePath = false;
     SkOpSpan* topSpan;
     globalState.setPhase(SkOpGlobalState::kFixWinding);
     while ((topSpan = FindSortableTop(&contourHead))) {
         SkOpSegment* topSegment = topSpan->segment();
         SkOpContour* topContour = topSegment->contour();
         SkASSERT(topContour->isCcw() >= 0);
 #if DEBUG_WINDING
         SkDebugf("%s id=%d nested=%d ccw=%d\n",  __FUNCTION__,
                 topSegment->debugID(), globalState.nested(), topContour->isCcw());
 #endif
         if ((globalState.nested() & 1) != SkToBool(topContour->isCcw())) {
             topContour->setReverse();
             writePath = true;
         }
-        topContour->markDone();
+        topContour->markAllDone();
         globalState.clearNested();
     }
     if (!writePath) {
         path->setFillType(fillType);
         return true;
     }
     SkPath empty;
     SkPathWriter woundPath(empty);
     SkOpContour* test = &contourHead;
     do {
@@ skipping 90 matching lines @@
             sum.addPath(fPathRefs[index]);
         }
     }
     reset();
     bool success = Simplify(sum, result);
     if (!success) {
         *result = original;
     }
     return success;
 }