diff --git a/tests/PathOpsCubicIntersectionTest.cpp b/tests/PathOpsCubicIntersectionTest.cpp
index d04f2db..109c42e 100644
--- a/tests/PathOpsCubicIntersectionTest.cpp
+++ b/tests/PathOpsCubicIntersectionTest.cpp
@@ -61,6 +61,7 @@
             }
             REPORTER_ASSERT(reporter, xy1.approximatelyEqual(xy2));
         }
+        reporter->bumpTestCount();
     }
 }
 
@@ -163,7 +164,17 @@
 const size_t testSetCount = SK_ARRAY_COUNT(testSet);
 
 static const SkDCubic newTestSet[] = {
-{{{134, 11414}, {131.990234375, 11414}, {130.32666015625, 11415.482421875}, {130.04275512695312, 11417.4130859375}}},
+#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
+
+{{{399,657}, {399,661.970581}, {403.029449,666}, {408,666}}},
+{{{406,666}, {402.686279,666}, {400,663.313721}, {400,660}}},
+
+{{{0,5}, {3,5}, {3,0}, {3,2}}},
+{{{0,3}, {2,3}, {5,0}, {5,3}}},
+
 {{{132, 11419}, {130.89543151855469, 11419}, {130, 11418.1044921875}, {130, 11417}}},
 
 {{{3, 4}, {1, 5}, {4, 3}, {6, 4}}},
@@ -283,7 +294,8 @@
 
 const size_t newTestSetCount = SK_ARRAY_COUNT(newTestSet);
 
-static void oneOff(skiatest::Reporter* reporter, const SkDCubic& cubic1, const SkDCubic& cubic2) {
+static void oneOff(skiatest::Reporter* reporter, const SkDCubic& cubic1, const SkDCubic& cubic2,
+        bool coin) {
     SkASSERT(ValidCubic(cubic1));
     SkASSERT(ValidCubic(cubic2));
 #if ONE_OFF_DEBUG
@@ -317,6 +329,7 @@
 #endif
     SkIntersections intersections;
     intersections.intersect(cubic1, cubic2);
+    REPORTER_ASSERT(reporter, !coin || intersections.used() == 2);
     double tt1, tt2;
     SkDPoint xy1, xy2;
     for (int pt3 = 0; pt3 < intersections.used(); ++pt3) {
@@ -334,18 +347,19 @@
        REPORTER_ASSERT(reporter, xy2.approximatelyEqual(iPt));
        REPORTER_ASSERT(reporter, xy1.approximatelyEqual(xy2));
     }
+    reporter->bumpTestCount();
 }
 
 static void oneOff(skiatest::Reporter* reporter, int outer, int inner) {
     const SkDCubic& cubic1 = testSet[outer];
     const SkDCubic& cubic2 = testSet[inner];
-    oneOff(reporter, cubic1, cubic2);
+    oneOff(reporter, cubic1, cubic2, false);
 }
 
 static void newOneOff(skiatest::Reporter* reporter, int outer, int inner) {
     const SkDCubic& cubic1 = newTestSet[outer];
     const SkDCubic& cubic2 = newTestSet[inner];
-    oneOff(reporter, cubic1, cubic2);
+    oneOff(reporter, cubic1, cubic2, false);
 }
 
 static void oneOffTests(skiatest::Reporter* reporter) {
@@ -412,6 +426,7 @@
             SkDPoint xy2 = cubic2.ptAtT(tt2);
             REPORTER_ASSERT(reporter, xy1.approximatelyEqual(xy2));
         }
+        reporter->bumpTestCount();
     }
 }
 
@@ -559,6 +574,7 @@
     SkDPoint pt1 = cubic.ptAtT(i[0][0]);
     SkDPoint pt2 = cubic.ptAtT(i[1][0]);
     REPORTER_ASSERT(reporter, pt1.approximatelyEqual(pt2));
+    reporter->bumpTestCount();
 }
 
 static void cubicIntersectionSelfTest(skiatest::Reporter* reporter) {
@@ -568,6 +584,34 @@
     }
 }
 
+static const SkDCubic coinSet[] = {
+    {{{317, 711}, {322.52285766601562, 711}, {327, 715.4771728515625}, {327, 721}}},
+    {{{324.07107543945312, 713.928955078125}, {324.4051513671875, 714.26300048828125},
+            {324.71566772460937, 714.62060546875}, {325, 714.9990234375}}},
+
+    {{{2, 3}, {0, 4}, {3, 2}, {5, 3}}},
+    {{{2, 3}, {0, 4}, {3, 2}, {5, 3}}},
+};
+
+size_t coinSetCount = SK_ARRAY_COUNT(coinSet);
+
+static void coinOneOff(skiatest::Reporter* reporter, int index) {
+    const SkDCubic& cubic1 = coinSet[index];
+    const SkDCubic& cubic2 = coinSet[index + 1];
+    oneOff(reporter, cubic1, cubic2, true);
+}
+
+static void cubicIntersectionCoinTest(skiatest::Reporter* reporter) {
+    size_t firstFail = 0;
+    for (size_t index = firstFail; index < coinSetCount; index += 2) {
+        coinOneOff(reporter, index);
+    }
+}
+
+static void PathOpsCubicCoinOneOffTest(skiatest::Reporter* reporter) {
+    coinOneOff(reporter, 0);
+}
+
 static void PathOpsCubicIntersectionOneOffTest(skiatest::Reporter* reporter) {
     newOneOff(reporter, 0, 1);
 }
@@ -579,6 +623,7 @@
 static void PathOpsCubicIntersectionTest(skiatest::Reporter* reporter) {
     oneOffTests(reporter);
     cubicIntersectionSelfTest(reporter);
+    cubicIntersectionCoinTest(reporter);
     standardTestCases(reporter);
     if (false) CubicIntersection_IntersectionFinder();
     if (false) CubicIntersection_RandTest(reporter);
@@ -590,3 +635,5 @@
 DEFINE_TESTCLASS_SHORT(PathOpsCubicIntersectionOneOffTest)
 
 DEFINE_TESTCLASS_SHORT(PathOpsCubicSelfOneOffTest)
+
+DEFINE_TESTCLASS_SHORT(PathOpsCubicCoinOneOffTest)