Reland of more zero-length changes for svg compatibility

src/core/SkStroke.cpp

Index: src/core/SkStroke.cpp
diff --git a/src/core/SkStroke.cpp b/src/core/SkStroke.cpp
index 1689f9730b008716e2217fb756953d2b48ede1b4..522a000712f875f22bcfa2fdee65eba13ba1a240 100644
--- a/src/core/SkStroke.cpp
+++ b/src/core/SkStroke.cpp
@@ -619,6 +619,10 @@
     SkPoint reduction;
     ReductionType reductionType = CheckConicLinear(conic, &reduction);
     if (kPoint_ReductionType == reductionType) {
+        /* If the stroke consists of a moveTo followed by a degenerate curve, treat it
+            as if it were followed by a zero-length line. Lines without length
+            can have square and round end caps. */
+        this->lineTo(pt2);
         return;
     }
     if (kLine_ReductionType == reductionType) {
@@ -653,6 +657,10 @@
     SkPoint reduction;
     ReductionType reductionType = CheckQuadLinear(quad, &reduction);
     if (kPoint_ReductionType == reductionType) {
+        /* If the stroke consists of a moveTo followed by a degenerate curve, treat it
+            as if it were followed by a zero-length line. Lines without length
+            can have square and round end caps. */
+        this->lineTo(pt2);
         return;
     }
     if (kLine_ReductionType == reductionType) {
@@ -1168,6 +1176,10 @@
     const SkPoint* tangentPt;
     ReductionType reductionType = CheckCubicLinear(cubic, reduction, &tangentPt);
     if (kPoint_ReductionType == reductionType) {
+        /* If the stroke consists of a moveTo followed by a degenerate curve, treat it
+            as if it were followed by a zero-length line. Lines without length
+            can have square and round end caps. */
+        this->lineTo(pt3);
         return;
     }
     if (kLine_ReductionType == reductionType) {