fix bugs found by computing flat clips in 800K skps

src/pathops/SkAddIntersections.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkAddIntersections.h"
 #include "SkPathOpsBounds.h"
 
 #if DEBUG_ADD_INTERSECTING_TS
@@ skipping 379 matching lines @@
                             ts.cleanUpCoincidence();  // prefer (t == 0 or t == 1)
                             pts = 1;
                         }
                     }
                 }
             }
             for (int pt = 0; pt < pts; ++pt) {
                 SkASSERT(ts[0][pt] >= 0 && ts[0][pt] <= 1);
                 SkASSERT(ts[1][pt] >= 0 && ts[1][pt] <= 1);
                 SkPoint point = ts.pt(pt).asSkPoint();
+                wt.alignTPt(wn, swap, pt, &ts, &point);
                 int testTAt = wt.addT(wn, point, ts[swap][pt]);
                 int nextTAt = wn.addT(wt, point, ts[!swap][pt]);
                 wt.addOtherT(testTAt, ts[!swap][pt], nextTAt);
                 wn.addOtherT(nextTAt, ts[swap][pt], testTAt);
             }
         } while (wn.advance());
     } while (wt.advance());
     return true;
 }
 
@@ skipping 20 matching lines @@
         wt.addOtherT(nextTAt, ts[0][0], testTAt);
     } while (wt.advance());
 }
 
 // resolve any coincident pairs found while intersecting, and
 // see if coincidence is formed by clipping non-concident segments
 void CoincidenceCheck(SkTArray<SkOpContour*, true>* contourList, int total) {
     int contourCount = (*contourList).count();
     for (int cIndex = 0; cIndex < contourCount; ++cIndex) {
         SkOpContour* contour = (*contourList)[cIndex];
+        contour->resolveNearCoincidence();
+    }
+    for (int cIndex = 0; cIndex < contourCount; ++cIndex) {
+        SkOpContour* contour = (*contourList)[cIndex];
         contour->addCoincidentPoints();
     }
     for (int cIndex = 0; cIndex < contourCount; ++cIndex) {
         SkOpContour* contour = (*contourList)[cIndex];
         contour->calcCoincidentWinding();
     }
     for (int cIndex = 0; cIndex < contourCount; ++cIndex) {
         SkOpContour* contour = (*contourList)[cIndex];
         contour->calcPartialCoincidentWinding();
     }
 }