fix cubic linear test

Check to see if the line between end points is
degenerate before measuring control points.

Also, add test case for a bug to see if it
shows up on any platform.

TBR=reed@google.com
BUG=skia:5169, skia:5240
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2375053002

Review-Url: https://codereview.chromium.org/2375053002

5 files changed, 30 insertions, 5 deletions

diff --git a/src/pathops/SkOpBuilder.cpp b/src/pathops/SkOpBuilder.cpp
index d0cb9c1de9..e4e7834392 100644
--- a/src/pathops/SkOpBuilder.cpp
+++ b/src/pathops/SkOpBuilder.cpp
@@ -53,7 +53,9 @@ bool FixWinding(SkPath* path) {
     if (!contourHead.count()) {
         return true;
     }
-    SkASSERT(contourHead.next());
+    if (!contourHead.next()) {
+        return false;
+    }
     contourHead.joinAllSegments();
     contourHead.resetReverse();
     bool writePath = false;
diff --git a/src/pathops/SkPathOpsCubic.cpp b/src/pathops/SkPathOpsCubic.cpp
index 6fcb348e4f..bdae492de0 100644
--- a/src/pathops/SkPathOpsCubic.cpp
+++ b/src/pathops/SkPathOpsCubic.cpp
@@ -212,6 +212,9 @@ bool SkDCubic::hullIntersects(const SkDConic& conic, bool* isLinear) const {
 }
 
 bool SkDCubic::isLinear(int startIndex, int endIndex) const {
+    if (fPts[0].approximatelyDEqual(fPts[3]))  {
+        return ((const SkDQuad *) this)->isLinear(0, 2);
+    }
     SkLineParameters lineParameters;
     lineParameters.cubicEndPoints(*this, startIndex, endIndex);
     // FIXME: maybe it's possible to avoid this and compare non-normalized
diff --git a/tests/PathOpsOpTest.cpp b/tests/PathOpsOpTest.cpp
index 5cd0e75501..1cc9ac4226 100644
--- a/tests/PathOpsOpTest.cpp
+++ b/tests/PathOpsOpTest.cpp
@@ -5395,6 +5395,17 @@ static void circlesOp4(skiatest::Reporter* reporter, const char* filename) {
     testPathOp(reporter, path, pathB, kDifference_SkPathOp, filename);
 }
 
+static void bug5240(skiatest::Reporter* reporter, const char* filename) {
+ SkPath path;
+path.moveTo(815, 82);
+path.cubicTo(814.4794311523438f, 82.7868881225586f, 814.5330810546875f,
+82.6266555786133f, 814.5291137695312f, 82.6252212524414f);
+path.cubicTo(814.5229492187500f, 82.6230010986328f, 814.3790283203125f,
+83.0008087158203f, 813.8533935546875f, 82.7072601318359f);
+path.close();
+    testPathOp(reporter, path, path, kUnion_SkPathOp, filename);
+}
+
 static void (*skipTest)(skiatest::Reporter* , const char* filename) = 0;
 static void (*firstTest)(skiatest::Reporter* , const char* filename) = 0;
 static void (*stopTest)(skiatest::Reporter* , const char* filename) = 0;
@@ -5402,6 +5413,7 @@ static void (*stopTest)(skiatest::Reporter* , const char* filename) = 0;
 #define TEST(name) { name, #name }
 
 static struct TestDesc tests[] = {
+    TEST(bug5240),
     TEST(circlesOp4),
     TEST(loop17),
     TEST(cubicOp158),
diff --git a/tests/PathOpsSimplifyFailTest.cpp b/tests/PathOpsSimplifyFailTest.cpp
index 359b12592b..fa168d9520 100644
--- a/tests/PathOpsSimplifyFailTest.cpp
+++ b/tests/PathOpsSimplifyFailTest.cpp
@@ -87,10 +87,8 @@ static void dontFailOne(skiatest::Reporter* reporter, int index) {
     SkPath result;
     result.setFillType(SkPath::kWinding_FillType);
     bool success = Simplify(path, &result);
-    if (index != 17 && index != 31 && index != 38) {  // cubic fails to chop in two without creating NaNs
-        REPORTER_ASSERT(reporter, success);
-        REPORTER_ASSERT(reporter, result.getFillType() != SkPath::kWinding_FillType);
-    }
+    REPORTER_ASSERT(reporter, success);
+    REPORTER_ASSERT(reporter, result.getFillType() != SkPath::kWinding_FillType);
     reporter->bumpTestCount();
 }
 
diff --git a/tests/PathOpsSimplifyTest.cpp b/tests/PathOpsSimplifyTest.cpp
index 37e50cae36..5a2f012cfc 100644
--- a/tests/PathOpsSimplifyTest.cpp
+++ b/tests/PathOpsSimplifyTest.cpp
@@ -5542,11 +5542,21 @@ static void testQuads73(skiatest::Reporter* reporter, const char* filename) {
     testSimplify(reporter, path, filename);
 }
 
+static void bug5169(skiatest::Reporter* reporter, const char* filename) {
+    SkPath path;
+path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x4281c71c));  // 0, 64.8889f
+path.cubicTo(SkBits2Float(0x434e0000), SkBits2Float(0x4281c71c), SkBits2Float(0x00000000), SkBits2Float(0xc2a238e4), SkBits2Float(0x00000000), SkBits2Float(0x4281c71c));  // 206, 64.8889f, 0, -81.1111f, 0, 64.8889f
+path.moveTo(SkBits2Float(0x43300000), SkBits2Float(0x41971c72));  // 176, 18.8889f
+path.cubicTo(SkBits2Float(0xc29e0000), SkBits2Float(0xc25c71c7), SkBits2Float(0x42b20000), SkBits2Float(0x42fbc71c), SkBits2Float(0x43300000), SkBits2Float(0x41971c72));  // -79, -55.1111f, 89, 125.889f, 176, 18.8889f
+    testSimplify(reporter, path, filename);
+}
+
 static void (*skipTest)(skiatest::Reporter* , const char* filename) = 0;
 static void (*firstTest)(skiatest::Reporter* , const char* filename) = 0;
 static void (*stopTest)(skiatest::Reporter* , const char* filename) = 0;
 
 static TestDesc tests[] = {
+    TEST(bug5169),
     TEST(testQuads73),
     TEST(testQuads72),
     TEST(testQuads71),