commit 5c5cfe24efe4c728e787447dabffe345080d1fb9
author caryclark <caryclark@google.com> Tue Apr 05 07:28:48 2016 -0700
committer Commit bot <commit-bot@chromium.org> Tue Apr 05 07:28:48 2016 -0700
tree c8b9c3d926c3e1806542c30b561a1be9dbceccce
parent 3b597388b35967a751fb055d0b8fcc30b443b5a8

give up if huge paths have unresolvable coincidence

This fuzzy test has enormous curves with coincidence runs that break numerics.
If the computed intersections identify that the span of coincidence has been deleted,
give up and return that the path op failed.

TBR=reed@google.com
BUG=597926
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1854333002

Review URL: https://codereview.chromium.org/1854333002

src/pathops/SkOpCoincidence.cpp

diff --git a/src/pathops/SkOpCoincidence.cpp b/src/pathops/SkOpCoincidence.cpp
index c0147bc..130d1da 100755
--- a/src/pathops/SkOpCoincidence.cpp
+++ b/src/pathops/SkOpCoincidence.cpp
@@ -634,16 +634,22 @@
 }
 
 /* this sets up the coincidence links in the segments when the coincidence crosses multiple spans */
-void SkOpCoincidence::mark() {
+bool SkOpCoincidence::mark() {
     SkCoincidentSpans* coin = fHead;
     if (!coin) {
-        return;
+        return true;
     }
     do {
         SkOpSpanBase* end = coin->fCoinPtTEnd->span();
+        if (end->deleted()) {
+          return false;
+        }
         SkOpSpanBase* oldEnd = end;
         SkOpSpan* start = coin->fCoinPtTStart->span()->starter(&end);
         SkOpSpanBase* oEnd = coin->fOppPtTEnd->span();
+        if (oEnd->deleted()) {
+          return false;
+        }
         SkOpSpanBase* oOldEnd = oEnd;
         SkOpSpanBase* oStart = coin->fOppPtTStart->span()->starter(&oEnd);
         bool flipped = (end == oldEnd) != (oEnd == oOldEnd);
@@ -668,6 +674,7 @@
             }
         } while (true);
     } while ((coin = coin->fNext));
+    return true;
 }
 
 bool SkOpCoincidence::overlap(const SkOpPtT* coin1s, const SkOpPtT* coin1e, 

src/pathops/SkOpCoincidence.h

diff --git a/src/pathops/SkOpCoincidence.h b/src/pathops/SkOpCoincidence.h
index 96bd21a..344866f 100644
--- a/src/pathops/SkOpCoincidence.h
+++ b/src/pathops/SkOpCoincidence.h
@@ -92,7 +92,7 @@
         return !fHead;
     }
 
-    void mark();
+    bool mark();
 
 private:
     bool addIfMissing(const SkCoincidentSpans* outer, SkOpPtT* over1s, SkOpPtT* over1e,

src/pathops/SkPathOpsCommon.cpp

diff --git a/src/pathops/SkPathOpsCommon.cpp b/src/pathops/SkPathOpsCommon.cpp
index 829f8a50..86a8cb0 100644
--- a/src/pathops/SkPathOpsCommon.cpp
+++ b/src/pathops/SkPathOpsCommon.cpp
@@ -494,7 +494,9 @@
     }
     DEBUG_COINCIDENCE_HEALTH(contourList, "expand2");
     // the expanded ranges may not align -- add the missing spans
-    coincidence->mark();  // mark spans of coincident segments as coincident
+    if (!coincidence->mark()) {  // mark spans of coincident segments as coincident
+        return false;
+    }
     DEBUG_COINCIDENCE_HEALTH(contourList, "mark1");
     // look for coincidence missed earlier
     if (missingCoincidence(contourList, coincidence, allocator)) {

tests/PathOpsOpTest.cpp

diff --git a/tests/PathOpsOpTest.cpp b/tests/PathOpsOpTest.cpp
index 1443198..2af9414 100644
--- a/tests/PathOpsOpTest.cpp
+++ b/tests/PathOpsOpTest.cpp
@@ -5792,7 +5792,31 @@
     testPathFailOp(reporter, path1, path2, (SkPathOp) 2, filename);
 }
 
+static void bug597926_0(skiatest::Reporter* reporter, const char* filename) {
+SkPath path;
+path.setFillType((SkPath::FillType) 0);
+path.moveTo(SkBits2Float(0x43b38000), SkBits2Float(0x433e0000));  // 359, 190
+path.lineTo(SkBits2Float(0x40c00000), SkBits2Float(0x449ce000));  // 6, 1255
+path.cubicTo(SkBits2Float(0x438c0000), SkBits2Float(0x4497a000), SkBits2Float(0x43e40000), SkBits2Float(0x44750000), SkBits2Float(0x41000000), SkBits2Float(0x44aa2000));  // 280, 1213, 456, 980, 8, 1361
+path.moveTo(SkBits2Float(0x43290000), SkBits2Float(0x4431c000));  // 169, 711
+path.lineTo(SkBits2Float(0xd987d6ba), SkBits2Float(0xd93d0ad4));  // -4.7794e+15f, -3.32567e+15f
+path.conicTo(SkBits2Float(0x43cc8000), SkBits2Float(0x445b8000), SkBits2Float(0xd888b096), SkBits2Float(0xd9a1ebfa), SkBits2Float(0x3ebcb199));  // 409, 878, -1.20234e+15f, -5.69712e+15f, 0.368542f
+path.cubicTo(SkBits2Float(0x43c00000), SkBits2Float(0x443a8000), SkBits2Float(0x42380000), SkBits2Float(0x4421c000), SkBits2Float(0x42500000), SkBits2Float(0x448ca000));  // 384, 746, 46, 647, 52, 1125
+path.quadTo(SkBits2Float(0x43948000), SkBits2Float(0x42ac0000), SkBits2Float(0x43880000), SkBits2Float(0x4487e000));  // 297, 86, 272, 1087
+SkPath path1(path);
+path.reset();
+path.setFillType((SkPath::FillType) 0);
+path.moveTo(SkBits2Float(0xc51d735c), SkBits2Float(0xc49db029));  // -2519.21f, -1261.51f
+path.cubicTo(SkBits2Float(0xc51d1dbd), SkBits2Float(0xc49d7a3f), SkBits2Float(0xc51c524a), SkBits2Float(0xc49d1610), SkBits2Float(0xc51d1a96), SkBits2Float(0xc49d86a6));  // -2513.86f, -1259.82f, -2501.14f, -1256.69f, -2513.66f, -1260.21f
+path.cubicTo(SkBits2Float(0xc51cd471), SkBits2Float(0xc49d54d0), SkBits2Float(0xc51c2e51), SkBits2Float(0xc49d0081), SkBits2Float(0xc51d197b), SkBits2Float(0xc49d7927));  // -2509.28f, -1258.65f, -2498.89f, -1256.02f, -2513.59f, -1259.79f
+path.quadTo(SkBits2Float(0xc51bf7eb), SkBits2Float(0xc49cf010), SkBits2Float(0xc51ba866), SkBits2Float(0xc49cb9e6));  // -2495.49f, -1255.5f, -2490.52f, -1253.81f
+path.cubicTo(SkBits2Float(0xc51bac0d), SkBits2Float(0xc49cc50e), SkBits2Float(0xc51c29eb), SkBits2Float(0xc49cfb01), SkBits2Float(0xc51c5bca), SkBits2Float(0xc49d1fa6));  // -2490.75f, -1254.16f, -2498.62f, -1255.84f, -2501.74f, -1256.99f
+SkPath path2(path);
+testPathFailOp(reporter, path1, path2, (SkPathOp) 1, filename);
+}
+
 static struct TestDesc failTests[] = {
+    TEST(bug597926_0),
     TEST(fuzz535151),
     TEST(fuzz753_91),
     TEST(fuzz714),