fix tiger b

src/pathops/SkOpAngle.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 "SkOpAngle.h"
 #include "SkOpSegment.h"
 #include "SkPathOpsCurve.h"
 #include "SkTSort.h"
@@ skipping 823 matching lines @@
 
 void SkOpAngle::setSpans() {
     fUnorderable = false;
     fLastMarked = nullptr;
     if (!fStart) {
         fUnorderable = true;
         return;
     }
     const SkOpSegment* segment = fStart->segment();
     const SkPoint* pts = segment->pts();
-    SkDEBUGCODE(fPart.fCurve.fVerb = SkPath::kCubic_Verb);
+    SkDEBUGCODE(fPart.fCurve.fVerb = SkPath::kCubic_Verb);  // required for SkDCurve debug check
     SkDEBUGCODE(fPart.fCurve[2].fX = fPart.fCurve[2].fY = fPart.fCurve[3].fX = fPart.fCurve[3].fY
-            = SK_ScalarNaN);
-    SkDEBUGCODE(fPart.fCurve.fVerb = segment->verb());
-    segment->subDivide(fStart, fEnd, &fPart.fCurve);
+            = SK_ScalarNaN);   //  make the non-line part uninitialized
+    SkDEBUGCODE(fPart.fCurve.fVerb = segment->verb());  //  set the curve type for real
+    segment->subDivide(fStart, fEnd, &fPart.fCurve);  //  set at least the line part if not more
     fOriginalCurvePart = fPart.fCurve;
     const SkPath::Verb verb = segment->verb();
     fPart.setCurveHullSweep(verb);
     if (SkPath::kLine_Verb != verb && !fPart.isCurve()) {
         SkDLine lineHalf;
         fPart.fCurve[1] = fPart.fCurve[SkPathOpsVerbToPoints(verb)];
         fOriginalCurvePart[1] = fPart.fCurve[1];
         lineHalf[0].set(fPart.fCurve[0].asSkPoint());
         lineHalf[1].set(fPart.fCurve[1].asSkPoint());
         fTangentHalf.lineEndPoints(lineHalf);
@@ skipping 138 matching lines @@
         return true;
     }
     SkASSERT(s0dt0 != 0);
     double m = s0xt0 / s0dt0;
     double sDist = sweep[0].length() * m;
     double tDist = tweep[0].length() * m;
     bool useS = fabs(sDist) < fabs(tDist);
     double mFactor = fabs(useS ? this->distEndRatio(sDist) : rh->distEndRatio(tDist));
     return mFactor < 50;   // empirically found limit
 }