fix pathops skp-derived bugs; add more failing tests

TBR=

Author: caryclark@google.com

Review URL: https://codereview.chromium.org/463883002
diff --git a/src/pathops/SkOpAngle.h b/src/pathops/SkOpAngle.h
index 63d378d..098c470 100644
--- a/src/pathops/SkOpAngle.h
+++ b/src/pathops/SkOpAngle.h
@@ -160,10 +160,10 @@
     void reset();
 private:
     void dump() const;  // utility to be called by user from debugger
+    SkChunkAlloc* fAngles;
 #if DEBUG_ANGLE
     int fCount;
 #endif
-    SkChunkAlloc* fAngles;
 };
 
 #endif
diff --git a/src/pathops/SkOpContour.cpp b/src/pathops/SkOpContour.cpp
index 5ef702d..e4dd62a 100644
--- a/src/pathops/SkOpContour.cpp
+++ b/src/pathops/SkOpContour.cpp
@@ -452,8 +452,14 @@
     }
     if (cancelers) {
         if (missingT1 >= 0) {
+            if (addTo1->reversePoints(missingPt1, missingPt2)) {
+                SkTSwap(missingPt1, missingPt2);
+            }
             addTo1->addTCancel(missingPt1, missingPt2, addOther1);
         } else {
+            if (addTo2->reversePoints(missingPt1, missingPt2)) {
+                SkTSwap(missingPt1, missingPt2);
+            }
             addTo2->addTCancel(missingPt1, missingPt2, addOther2);
         }
     } else if (missingT1 >= 0) {
diff --git a/src/pathops/SkOpSegment.cpp b/src/pathops/SkOpSegment.cpp
index f6d989b..747cd9d 100644
--- a/src/pathops/SkOpSegment.cpp
+++ b/src/pathops/SkOpSegment.cpp
@@ -2294,9 +2294,10 @@
         }
         const SkOpSpan& firstSpan = this->firstSpan(*thisSpan);
         const SkOpSpan& lastSpan = this->lastSpan(*thisSpan);
+        const SkOpSpan* nextSpan = &firstSpan + 1;
         ptrdiff_t smallCount = &lastSpan - &firstSpan + 1;
         SkASSERT(1 <= smallCount && smallCount < count());
-        if (smallCount <= 1) {
+        if (smallCount <= 1 && !nextSpan->fSmall) {
             SkASSERT(1 == smallCount);
             checkSmallCoincidence(firstSpan, NULL);
             continue;
@@ -3067,6 +3068,13 @@
 
 int SkOpSegment::findT(double t, const SkPoint& pt, const SkOpSegment* match) const {
     int count = this->count();
+    // prefer exact matches over approximate matches
+    for (int index = 0; index < count; ++index) {
+        const SkOpSpan& span = fTs[index];
+        if (span.fT == t && span.fOther == match) {
+            return index;
+        }
+    }
     for (int index = 0; index < count; ++index) {
         const SkOpSpan& span = fTs[index];
         if (approximately_equal_orderable(span.fT, t) && span.fOther == match) {
@@ -3986,6 +3994,24 @@
     }
 }
 
+bool SkOpSegment::reversePoints(const SkPoint& p1, const SkPoint& p2) const {
+    SkASSERT(p1 != p2);
+    int spanCount = count();
+    int p1IndexMin = -1;
+    int p2IndexMax = spanCount;
+    for (int index = 0; index < spanCount; ++index) {
+        const SkOpSpan& span = fTs[index];
+        if (span.fPt == p1) {
+            if (p1IndexMin < 0) {
+                p1IndexMin = index;
+            }
+        } else if (span.fPt == p2) {
+            p2IndexMax = index;
+        }
+    }
+    return p1IndexMin > p2IndexMax;
+}
+
 void SkOpSegment::setCoincidentRange(const SkPoint& startPt, const SkPoint& endPt, 
         SkOpSegment* other) {
     int count = this->count();
diff --git a/src/pathops/SkOpSegment.h b/src/pathops/SkOpSegment.h
index d191e88..df87d05 100644
--- a/src/pathops/SkOpSegment.h
+++ b/src/pathops/SkOpSegment.h
@@ -177,6 +177,8 @@
         fTs.reset();
     }
 
+    bool reversePoints(const SkPoint& p1, const SkPoint& p2) const;
+
     void setOppXor(bool isOppXor) {
         fOppXor = isOppXor;
     }
diff --git a/tests/PathOpsSkpClipTest.cpp b/tests/PathOpsSkpClipTest.cpp
index 0e3cee9..a94412e 100755
--- a/tests/PathOpsSkpClipTest.cpp
+++ b/tests/PathOpsSkpClipTest.cpp
@@ -38,7 +38,7 @@
     { 7, "http___www_foxsports_nl_.skp", true},  // (no repro on mac) addT SkASSERT(this != other || fVerb == SkPath::kCubic_Verb)
     {13, "http___www_modernqigong_com_.skp", false},  // SkAAClip::Builder::addRun SkASSERT(fBounds.contains(x, y));
     {14, "http___www_devbridge_com_.skp", true},  // checkSmallCoincidence SkASSERT(!next->fSmall || checkMultiple);
-    {16, "http___www_1023world_net_.skp", true},  // bitmap decode assert (corrupt skp?)
+    {16, "http___www_1023world_net_.skp", false},  // bitmap decode assert (corrupt skp?)
     {19, "http___www_alamdi_com_.skp", true},  // cubic/quad intersection
     {26, "http___www_liveencounters_net_.skp", true},  // (no repro on mac) checkSmall addT:549 (line, expects cubic)
     {28, "http___www_encros_fr_.skp", false},  // SkAAClip::Builder::addRun SkASSERT(fBounds.contains(x, y));
diff --git a/tests/PathOpsSkpTest.cpp b/tests/PathOpsSkpTest.cpp
index 2da38f4..32ddf61 100755
--- a/tests/PathOpsSkpTest.cpp
+++ b/tests/PathOpsSkpTest.cpp
@@ -3571,8 +3571,6 @@
     testPathOp(reporter, path, pathB, kIntersect_PathOp, filename);
 }
 
-#if TEST_NEW_FAILURES
-// addTCoincident SkASSERT(test->fT < 1);
 static void skpwww_googleventures_com_32(skiatest::Reporter* reporter, const char* filename) {
     SkPath path;
     path.setFillType(SkPath::kEvenOdd_FillType);
@@ -3592,7 +3590,7 @@
     testPathOp(reporter, path, pathB, kIntersect_PathOp, filename);
 }
 
-// checkSmallCoincidence failed assertion "!next->fSmall || checkMultiple"
+#if TEST_NEW_FAILURES
 static void skpwww_devbridge_com_22(skiatest::Reporter* reporter, const char* filename) {
     SkPath path;
     path.setFillType(SkPath::kEvenOdd_FillType);
@@ -3672,8 +3670,8 @@
     pathB.lineTo(165, 14557);
     testPathOp(reporter, path, pathB, kIntersect_PathOp, filename);
 }
+#endif
 
-// addTCancel: failed assertion "oIndex > 0"
 static void skpwww_firstunitedbank_com_19(skiatest::Reporter* reporter, const char* filename) {
     SkPath path;
     path.setFillType(SkPath::kEvenOdd_FillType);
@@ -3709,7 +3707,6 @@
     pathB.lineTo(1047, 11703);
     testPathOp(reporter, path, pathB, kIntersect_PathOp, filename);
 }
-#endif
 
 // addSimpleAngle: failed assertion "index == count() - 2"
 static void skpwww_shinydemos_com_5(skiatest::Reporter* reporter, const char* filename) {
@@ -3764,17 +3761,77 @@
     testPathOp(reporter, path, pathB, kIntersect_PathOp, filename);
 }
 
+#if TEST_NEW_FAILURES
+// SkOpSegment.cpp:3915: failed assertion "otherEnd >= 0"
+static void skpwww_shinydemos_com_15(skiatest::Reporter* reporter, const char* filename) {
+    SkPath path;
+    path.setFillType(SkPath::kEvenOdd_FillType);
+    path.moveTo(1000, 310.947968f);
+    path.lineTo(771.570374f, 82.5183716f);
+    path.lineTo(205.884888f, 648.203857f);
+    path.lineTo(448.68103f, 891);
+    path.lineTo(641.911255f, 891);
+    path.lineTo(1000, 532.911316f);
+    path.lineTo(1000, 310.947968f);
+    path.close();
+    SkPath pathB;
+    pathB.setFillType(SkPath::kWinding_FillType);
+    pathB.moveTo(771.570374f, 82.5183716f);
+    pathB.lineTo(1110.98169f, 421.929626f);
+    pathB.lineTo(545.296204f, 987.615051f);
+    pathB.lineTo(205.884949f, 648.203796f);
+    pathB.close();
+    testPathOp(reporter, path, pathB, kIntersect_PathOp, filename);
+}
+
+// SkOpSegment.cpp:4398: failed assertion "!span->fDone"
+static void skpwww_lptemp_com_5(skiatest::Reporter* reporter, const char* filename) {
+    SkPath path;
+    path.setFillType(SkPath::kEvenOdd_FillType);
+    path.moveTo(78.6429825f, 3150.97632f);
+    path.quadTo(79.6192932f, 3150, 81.0000076f, 3150);
+    path.lineTo(341, 3150);
+    path.quadTo(342.380707f, 3150, 343.357025f, 3150.97632f);
+    path.quadTo(344.333344f, 3151.95264f, 344.333344f, 3153.33325f);
+    path.lineTo(344.333344f, 5205.3335f);
+    path.quadTo(344.333344f, 5206.71436f, 343.357025f, 5207.69092f);
+    path.quadTo(342.380707f, 5208.66699f, 341, 5208.66699f);
+    path.lineTo(81.0000076f, 5208.66699f);
+    path.quadTo(79.6192932f, 5208.66699f, 78.6429825f, 5207.69092f);
+    path.quadTo(77.6666718f, 5206.71436f, 77.6666718f, 5205.3335f);
+    path.lineTo(77.6666718f, 3153.33325f);
+    path.quadTo(77.6666718f, 3151.95264f, 78.6429825f, 3150.97632f);
+    path.close();
+    SkPath pathB;
+    pathB.setFillType(SkPath::kEvenOdd_FillType);
+    pathB.moveTo(81, 3150);
+    pathB.lineTo(341, 3150);
+    pathB.cubicTo(342.840942f, 3150, 344.333344f, 3151.49268f, 344.333344f, 3153.3335f);
+    pathB.lineTo(344.333344f, 5205.3335f);
+    pathB.cubicTo(344.333344f, 5206.99023f, 342.840942f, 5208.3335f, 341, 5208.3335f);
+    pathB.lineTo(81, 5208.3335f);
+    pathB.cubicTo(79.15905f, 5208.3335f, 77.6666718f, 5206.99023f, 77.6666718f, 5205.3335f);
+    pathB.lineTo(77.6666718f, 3153.3335f);
+    pathB.cubicTo(77.6666718f, 3151.49268f, 79.15905f, 3150, 81, 3150);
+    pathB.close();
+    testPathOp(reporter, path, pathB, kIntersect_PathOp, filename);
+}
+#endif
+
 static void (*firstTest)(skiatest::Reporter* , const char* filename) = 0;
 
 static struct TestDesc tests[] = {
     TEST(skpwww_lptemp_com_3),
     TEST(skpwww_shinydemos_com_5),
 #if TEST_NEW_FAILURES
+    TEST(skpwww_lptemp_com_5),
+    TEST(skpwww_shinydemos_com_15),
     TEST(skpwww_familysurvivalprotocol_wordpress_com_61),
     TEST(skpwww_alamdi_com_3),
     TEST(skpwww_devbridge_com_22),
-    TEST(skpwww_googleventures_com_32),
 #endif
+    TEST(skpwww_firstunitedbank_com_19),
+    TEST(skpwww_googleventures_com_32),
     TEST(skpwww_9to5mac_com_64),
     TEST(skpwww_wartepop_blogspot_com_br_6),
     TEST(skpwww_wartepop_blogspot_com_br_6a),