fix security bug

src/pathops/SkPathOpsTSect.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkPathOpsTSect_DEFINED
 #define SkPathOpsTSect_DEFINED
 
 #include "SkChunkAlloc.h"
@@ skipping 494 matching lines @@
         SkASSERT(ptsInCommon);
         return 2;
     }
     bool linear;
     if (fPart.hullIntersects(opp->fPart, &linear)) {
         if (!linear) {  // check set true if linear
             return 1;
         }
         fIsLinear = true;
         fIsLine = fPart.controlsInside();
-        return ptsInCommon ? 2 : -1;
+        return ptsInCommon ? 1 : -1;
     } else {  // hull is not linear; check set true if intersected at the end points
         return ((int) ptsInCommon) << 1;  // 0 or 2
     }
     return 0;
 }
 
 // OPTIMIZE ? If at_most_end_pts_in_common detects that one quad is near linear,
 // use line intersection to guess a better split than 0.5
 // OPTIMIZE Once at_most_end_pts_in_common detects linear, mark span so all future splits are linear
 template<typename TCurve, typename OppCurve>
@@ skipping 1712 matching lines @@
             --last;
         } else {
             intersections->setCoincident(index++);
         }
         intersections->setCoincident(index);
     }
     SkASSERT(intersections->used() <= TCurve::kMaxIntersections);
 }
 
 #endif