diff --git a/src/pathops/SkOpSegment.cpp b/src/pathops/SkOpSegment.cpp
index f3f8747..a1818d3 100644
--- a/src/pathops/SkOpSegment.cpp
+++ b/src/pathops/SkOpSegment.cpp
@@ -837,12 +837,19 @@
     markDone(minSpan);
     SkOpSpanBase* last = nullptr;
     SkOpSegment* other = this;
+    SkOpSpan* priorDone = nullptr;
+    SkOpSpan* lastDone = nullptr;
     while ((other = other->nextChase(&start, &step, &minSpan, &last))) {
         if (other->done()) {
             SkASSERT(!last);
             break;
         }
+        if (lastDone == minSpan || priorDone == minSpan) {
+            return nullptr;
+        }
         other->markDone(minSpan);
+        priorDone = lastDone;
+        lastDone = minSpan;
     }
     return last;
 }
diff --git a/src/pathops/SkPathOpsDebug.cpp b/src/pathops/SkPathOpsDebug.cpp
index 58b33c0..0906c45 100644
--- a/src/pathops/SkPathOpsDebug.cpp
+++ b/src/pathops/SkPathOpsDebug.cpp
@@ -13,7 +13,7 @@
 #include "SkPathOpsDebug.h"
 #include "SkString.h"
 
-#ifdef SK_DEBUG
+#if DEBUG_DUMP_VERIFY
 bool SkPathOpsDebug::gDumpOp;  // set to true to write op to file before a crash
 bool SkPathOpsDebug::gVerifyOp;  // set to true to compare result against regions
 #endif
@@ -2906,7 +2906,7 @@
     showPathContours(iter, name);
 }
 
-#ifdef SK_DEBUG
+#if DEBUG_DUMP_VERIFY
 #include "SkData.h"
 #include "SkStream.h"
 
diff --git a/src/pathops/SkPathOpsDebug.h b/src/pathops/SkPathOpsDebug.h
index 0258d58..aba02b1 100644
--- a/src/pathops/SkPathOpsDebug.h
+++ b/src/pathops/SkPathOpsDebug.h
@@ -58,6 +58,7 @@
 #define DEBUG_CUBIC_BINARY_SEARCH 0
 #define DEBUG_CUBIC_SPLIT 0
 #define DEBUG_DUMP_SEGMENTS 0
+#define DEBUG_DUMP_VERIFY 0
 #define DEBUG_FLOW 0
 #define DEBUG_LIMIT_WIND_SUM 0
 #define DEBUG_MARK_DONE 0
@@ -87,6 +88,7 @@
 #define DEBUG_COINCIDENCE_VERBOSE 01
 #define DEBUG_CUBIC_BINARY_SEARCH 0
 #define DEBUG_CUBIC_SPLIT 1
+#define DEBUG_DUMP_VERIFY 0
 #define DEBUG_DUMP_SEGMENTS 1
 #define DEBUG_FLOW 1
 #define DEBUG_LIMIT_WIND_SUM 15
@@ -375,7 +377,7 @@
     static bool gRunFail;
     static bool gVeryVerbose;
 
-#ifdef SK_DEBUG
+#if DEBUG_DUMP_VERIFY
     static bool gDumpOp;
     static bool gVerifyOp;
 
diff --git a/src/pathops/SkPathOpsOp.cpp b/src/pathops/SkPathOpsOp.cpp
index f423ba9..f6b08ea 100644
--- a/src/pathops/SkPathOpsOp.cpp
+++ b/src/pathops/SkPathOpsOp.cpp
@@ -223,7 +223,10 @@
     SkOpGlobalState globalState(contourList, &allocator
             SkDEBUGPARAMS(skipAssert) SkDEBUGPARAMS(testName));
     SkOpCoincidence coincidence(&globalState);
-#ifdef SK_DEBUG
+#if DEBUG_DUMP_VERIFY
+#ifndef SK_DEBUG
+    const char* testName = "release";
+#endif
     if (SkPathOpsDebug::gDumpOp) {
         SkPathOpsDebug::DumpOp(one, two, op, testName);
     }
@@ -316,7 +319,7 @@
 }
 
 bool Op(const SkPath& one, const SkPath& two, SkPathOp op, SkPath* result) {
-#ifdef SK_DEBUG
+#if DEBUG_DUMP_VERIFY
     if (SkPathOpsDebug::gVerifyOp) {
         if (!OpDebug(one, two, op, result  SkDEBUGPARAMS(false) SkDEBUGPARAMS(nullptr))) {
             SkPathOpsDebug::ReportOpFail(one, two, op);
diff --git a/src/pathops/SkPathOpsSimplify.cpp b/src/pathops/SkPathOpsSimplify.cpp
index d587c3b..8cd770d 100644
--- a/src/pathops/SkPathOpsSimplify.cpp
+++ b/src/pathops/SkPathOpsSimplify.cpp
@@ -158,7 +158,10 @@
     SkOpGlobalState globalState(contourList, &allocator
             SkDEBUGPARAMS(skipAssert) SkDEBUGPARAMS(testName));
     SkOpCoincidence coincidence(&globalState);
-#ifdef SK_DEBUG
+#if DEBUG_DUMP_VERIFY
+#ifndef SK_DEBUG
+    const char* testName = "release";
+#endif
     if (SkPathOpsDebug::gDumpOp) {
         SkPathOpsDebug::DumpSimplify(path, testName);
     }
@@ -223,7 +226,7 @@
 }
 
 bool Simplify(const SkPath& path, SkPath* result) {
-#ifdef SK_DEBUG
+#if DEBUG_DUMP_VERIFY
     if (SkPathOpsDebug::gVerifyOp) {
         if (!SimplifyDebug(path, result  SkDEBUGPARAMS(false) SkDEBUGPARAMS(nullptr))) {
             SkPathOpsDebug::ReportSimplifyFail(path);
diff --git a/tests/PathOpsOpTest.cpp b/tests/PathOpsOpTest.cpp
index f5bbfcd..6825095 100644
--- a/tests/PathOpsOpTest.cpp
+++ b/tests/PathOpsOpTest.cpp
@@ -8348,7 +8348,34 @@
     testPathOpFuzz(reporter, path1, path2, (SkPathOp) 0, filename);
 }
 
+static void fuzzhang_1(skiatest::Reporter* reporter, const char* filename) {
+    SkPath path;
+    path.setFillType((SkPath::FillType) 1);
+path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000));  // 0, 0
+path.cubicTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000), SkBits2Float(0x668ece09), SkBits2Float(0x00000000), SkBits2Float(0x6751c81a), SkBits2Float(0x61c4b0fb));  // 0, 0, 3.37188e+23f, 0, 9.90666e+23f, 4.53539e+20f
+path.conicTo(SkBits2Float(0x66f837a9), SkBits2Float(0x00000000), SkBits2Float(0x00000000), SkBits2Float(0x00000000), SkBits2Float(0x3f823406));  // 5.86087e+23f, 0, 0, 0, 1.01721f
+path.close();
+path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000));  // 0, 0
+path.quadTo(SkBits2Float(0x675b1bfe), SkBits2Float(0x00000000), SkBits2Float(0x67d76c42), SkBits2Float(0x6292c469));  // 1.03471e+24f, 0, 2.03461e+24f, 1.35369e+21f
+path.cubicTo(SkBits2Float(0x6a16df68), SkBits2Float(0x651a2f15), SkBits2Float(0x6c1e7f31), SkBits2Float(0x67a1f9b4), SkBits2Float(0x00000000), SkBits2Float(0x6a2a291f));  // 4.55985e+25f, 4.55071e+22f, 7.66444e+26f, 1.52981e+24f, 0, 5.14279e+25f
+path.conicTo(SkBits2Float(0x680dcb75), SkBits2Float(0x68dd898d), SkBits2Float(0x681a434a), SkBits2Float(0x6871046b), SkBits2Float(0x3fea0440));  // 2.67843e+24f, 8.36944e+24f, 2.91394e+24f, 4.55269e+24f, 1.82825f
+path.quadTo(SkBits2Float(0x679e1b26), SkBits2Float(0x687703c4), SkBits2Float(0x00000000), SkBits2Float(0x687d2968));  // 1.49327e+24f, 4.66598e+24f, 0, 4.78209e+24f
+path.lineTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000));  // 0, 0
+path.close();
+
+    SkPath path1(path);
+    path.reset();
+    path.setFillType((SkPath::FillType) 0);
+path.moveTo(SkBits2Float(0x00000000), SkBits2Float(0x00000000));  // 0, 0
+path.cubicTo(SkBits2Float(0x535353ec), SkBits2Float(0x98989898), SkBits2Float(0x98989898), SkBits2Float(0xf207f36e), SkBits2Float(0xf3f2f2f2), SkBits2Float(0xed3a9781));  // 9.07646e+11f, -3.94452e-24f, -3.94452e-24f, -2.69278e+30f, -3.84968e+31f, -3.60921e+27f
+path.quadTo(SkBits2Float(0xf8f8c0ed), SkBits2Float(0xf8f8f8f8), SkBits2Float(0x9f9f9f9f), SkBits2Float(0x3014149f));  // -4.03626e+34f, -4.03981e+34f, -6.76032e-20f, 5.38714e-10f
+
+    SkPath path2(path);
+    testPathOp(reporter, path1, path2, (SkPathOp) 0, filename);
+}
+
 static struct TestDesc failTests[] = {
+    TEST(fuzzhang_1),
     TEST(fuzz763_57),
     TEST(fuzz763_56),
     TEST(fuzz763_55),
diff --git a/tests/skia_test.cpp b/tests/skia_test.cpp
index 93b6c69..4cb55d0 100644
--- a/tests/skia_test.cpp
+++ b/tests/skia_test.cpp
@@ -137,7 +137,7 @@
 
 int test_main();
 int test_main() {
-#ifdef SK_DEBUG
+#if DEBUG_DUMP_VERIFY
     SkPathOpsDebug::gDumpOp = FLAGS_dumpOp;
     SkPathOpsDebug::gVerifyOp = FLAGS_verifyOp;
 #endif