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, 
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,
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)) {
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),