allow conic chop to fail

src/core/SkPathMeasure.cpp

 /*
  * Copyright 2008 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkPathMeasure.h"
 #include "SkPathMeasurePriv.h"
@@ skipping 67 matching lines @@
             }
             break;
         case kConic_SegType: {
             SkConic conic(pts[0], pts[2], pts[3], pts[1].fX);
 
             if (0 == startT) {
                 if (SK_Scalar1 == stopT) {
                     dst->conicTo(conic.fPts[1], conic.fPts[2], conic.fW);
                 } else {
                     SkConic tmp[2];
-                    conic.chopAt(stopT, tmp);
-                    dst->conicTo(tmp[0].fPts[1], tmp[0].fPts[2], tmp[0].fW);
+                    if (conic.chopAt(stopT, tmp)) {
+                        dst->conicTo(tmp[0].fPts[1], tmp[0].fPts[2], tmp[0].fW);
+                    }
                 }
             } else {
                 if (SK_Scalar1 == stopT) {
                     SkConic tmp1[2];
-                    conic.chopAt(startT, tmp1);
-                    dst->conicTo(tmp1[1].fPts[1], tmp1[1].fPts[2], tmp1[1].fW);
+                    if (conic.chopAt(startT, tmp1)) {
+                        dst->conicTo(tmp1[1].fPts[1], tmp1[1].fPts[2], tmp1[1].fW);
+                    }
                 } else {
                     SkConic tmp;
                     conic.chopAt(startT, stopT, &tmp);
                     dst->conicTo(tmp.fPts[1], tmp.fPts[2], tmp.fW);
                 }
             }
         } break;
         case kCubic_SegType:
             if (0 == startT) {
                 if (SK_Scalar1 == stopT) {
@@ skipping 591 matching lines @@
 
     for (int i = 0; i < fSegments.count(); i++) {
         const Segment* seg = &fSegments[i];
         SkDebugf("pathmeas: seg[%d] distance=%g, point=%d, t=%g, type=%d\n",
                 i, seg->fDistance, seg->fPtIndex, seg->getScalarT(),
                  seg->fType);
     }
 }
 
 #endif