fix bugs found by computing flat clips in 800K skps

tests/PathOpsCubicIntersectionTest.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 "PathOpsCubicIntersectionTestData.h"
 #include "PathOpsTestCommon.h"
 #include "SkIntersections.h"
 #include "SkPathOpsRect.h"
@@ skipping 144 matching lines @@
 
 {{{18.1312339, 31.6473732}, {95.5711034, 63.5350219}, {92.3283165, 62.0158945},
         {18.5656052, 32.1268808}}},
 {{{97.402018, 35.7169972}, {33.1127443, 25.8935163}, {1.13970027, 54.9424981},
         {56.4860195, 60.529264}}},
 };
 
 const int testSetCount = (int) SK_ARRAY_COUNT(testSet);
 
 static const SkDCubic newTestSet[] = {
+{{{980.9000244140625, 1474.3280029296875}, {980.9000244140625, 1474.3280029296875}, {978.89300537109375, 1471.95703125}, {981.791015625, 1469.487060546875}}},
+{{{981.791015625, 1469.487060546875}, {981.791015625, 1469.4859619140625}, {983.3580322265625, 1472.72900390625}, {980.9000244140625, 1474.3280029296875}}},
+
 {{{275,532}, {277.209137,532}, {279,530.209106}, {279,528}}},
 {{{278,529}, {278,530.65686}, {276.65686,532}, {275,532}}},
 
 #if 0  // FIXME: asserts coincidence, not working yet
 {{{195, 785}, {124.30755615234375, 785}, {67, 841.85986328125}, {67, 912}}},
 {{{67, 913}, {67, 842.30755615234375}, {123.85984039306641, 785}, {194, 785}}},
 #endif
 
 {{{149,710.001465}, {149.000809,712.209961}, {150.791367,714}, {153,714}}},
 {{{154,715}, {151.238571,715}, {149,712.761414}, {149,710}}},
@@ skipping 457 matching lines @@
 }
 
 DEF_TEST(PathOpsCubicIntersection, reporter) {
     oneOffTests(reporter);
     cubicIntersectionSelfTest(reporter);
     cubicIntersectionCoinTest(reporter);
     standardTestCases(reporter);
     if (false) CubicIntersection_IntersectionFinder();
     if (false) CubicIntersection_RandTest(reporter);
 }