update pathops core and tests

src/pathops/SkDLineIntersection.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 "SkIntersections.h"
 #include "SkPathOpsLine.h"
 
 /* Determine the intersection point of two lines. This assumes the lines are not parallel,
@@ skipping 155 matching lines @@
         bool aNotB[2] = {false, false};
         bool bNotA[2] = {false, false};
         int nearCount = 0;
         for (int index = 0; index < 2; ++index) {
             aNearB[index] = t = b.nearPoint(a[index], &aNotB[index]);
             nearCount += t >= 0;
             bNearA[index] = t = a.nearPoint(b[index], &bNotA[index]);
             nearCount += t >= 0;
         }
         if (nearCount > 0) {
-            for (int iA = 0; iA < 2; ++iA) {
-                if (!aNotB[iA]) {
-                    continue;
+            // Skip if each segment contributes to one end point.
+            if (nearCount != 2 || aNotB[0] == aNotB[1]) {
+                for (int iA = 0; iA < 2; ++iA) {
+                    if (!aNotB[iA]) {
+                        continue;
+                    }
+                    int nearer = aNearB[iA] > 0.5;
+                    if (!bNotA[nearer]) {
+                        continue;
+                    }
+                    SkASSERT(a[iA] != b[nearer]);
+                    SkASSERT(iA == (bNearA[nearer] > 0.5));
+                    fNearlySame[iA] = true;
+                    insertNear(iA, nearer, a[iA], b[nearer]);
+                    aNearB[iA] = -1;
+                    bNearA[nearer] = -1;
+                    nearCount -= 2;
                 }
-                int nearer = aNearB[iA] > 0.5;
-                if (!bNotA[nearer]) {
-                    continue;
-                }
-                SkASSERT(a[iA] != b[nearer]);
-                SkASSERT(iA == (bNearA[nearer] > 0.5));
-                fNearlySame[iA] = true;
-                insertNear(iA, nearer, a[iA], b[nearer]);
-                aNearB[iA] = -1;
-                bNearA[nearer] = -1;
-                nearCount -= 2;
             }
             if (nearCount > 0) {
                 for (int iA = 0; iA < 2; ++iA) {
                     if (aNearB[iA] >= 0) {
                         insert(iA, aNearB[iA], a[iA]);
                     }
                 }
                 for (int iB = 0; iB < 2; ++iB) {
                     if (bNearA[iB] >= 0) {
                         insert(bNearA[iB], iB, b[iB]);
@@ skipping 188 matching lines @@
 // 4 subs, 2 muls, 1 cmp
 static bool ccw(const SkDPoint& A, const SkDPoint& B, const SkDPoint& C) {
     return (C.fY - A.fY) * (B.fX - A.fX) > (B.fY - A.fY) * (C.fX - A.fX);
 }
 
 // 16 subs, 8 muls, 6 cmps
 bool SkIntersections::Test(const SkDLine& a, const SkDLine& b) {
     return ccw(a[0], b[0], b[1]) != ccw(a[1], b[0], b[1])
             && ccw(a[0], a[1], b[0]) != ccw(a[0], a[1], b[1]);
 }