remove duplicate linked list adjustment

The list of intersection points on a curve segment may have
entries that can be safely removed when nearby points have
nearly the same t value and point value. When a path includes
very large curves as well as small ones, as is the case with
this fuzzer, additional points may lie between the similar
points that do not meet the nearby criteria.

After merging the nearby point with its doppelganger,
SkOpSegment::moveNearby() unnecessarily set the doppelganger's
next pointer to the one following the nearby point. While
this usually has no effect, since the merge already updated
the linked list, the explicit call removes the additional
outlier points from the segment.

TBR=reed@google.com
BUG=526025

Review URL: https://codereview.chromium.org/1323813003

1 files changed, 23 insertions, 0 deletions

diff --git a/tests/PathOpsBuilderTest.cpp b/tests/PathOpsBuilderTest.cpp
index 88684fe18d..88bfe1e554 100644
--- a/tests/PathOpsBuilderTest.cpp
+++ b/tests/PathOpsBuilderTest.cpp
@@ -271,3 +271,26 @@ DEF_TEST(Fuzz846, reporter) {
     builder.resolve(&result);
 }
 
+#include "SkParsePath.h"
+
+DEF_TEST(fuzzTNG, reporter) {
+    const char* pathStrs[] = {
+"M360,-2147483648.000000000000000000000000000000000000000000000000000001 A3240,3240 0.0 0 11 256,256 L100000000,4140 Z",
+"M360,4140 A11,-1 0.0 0 0 6840,4140 L100,512 L32,16 L360,1024 Z",
+"M360,4140 A3240,1000000001 32768 1024 128 100000000.000000000000000000000000000000000000000000000000000001,512 Z",
+"M127,321 L6840,270 L-21474836481,100000000 L2551,64 Z",
+"M-128,4140 Z",
+    };
+    SkPath clip[SK_ARRAY_COUNT(pathStrs)];
+    SkOpBuilder builder;
+    for (size_t i = 0; i < SK_ARRAY_COUNT(pathStrs); ++i) {
+        SkParsePath::FromSVGString(pathStrs[i], &clip[i]);
+        builder.add(clip[i], kUnion_SkPathOp);
+    }
+    SkPath result;
+    builder.resolve(&result);
+    SkPath path;
+    SkParsePath::FromSVGString("M-315,7425 L4096,7425 L-1000000001,-315 L-315,7425 Z", &path);
+    builder.add(path, kDifference_SkPathOp);
+    testPathOp(reporter, result, path, kDifference_SkPathOp, __FUNCTION__);
+}