Merge pull request #565 from JordanMartinez/fixEitherOpsBug

Fix either ops bug

Author: JordanMartinez

richtextfx/src/main/java/org/fxmisc/richtext/model/Paragraph.java

@@ -171,7 +171,11 @@ public Paragraph<PS, SEG, S> subSequence(int start) {
             throw new IllegalArgumentException("start must not be negative (was: " + start + ")");
         } else if(start == 0) {
             return this;
-        } else if(start <= length()) {
+        } else if (start == length()) {
+            // in case one is using EitherOps<SegmentOps, SegmentOps>, force the empty segment
+            // to use the left ops' default empty seg, not the right one's empty seg
+            return new Paragraph<>(paragraphStyle, segmentOps, segmentOps.createEmpty());
+        } else if(start < length()) {
             Position pos = navigator.offsetToPosition(start, Forward);
             int segIdx = pos.getMajor();
             List<SEG> segs = new ArrayList<>(segments.size() - segIdx);

richtextfx/src/main/java/org/fxmisc/richtext/model/StyledText.java

@@ -143,8 +143,9 @@ public String toString() {
     public boolean equals(Object obj) {
         if(obj instanceof StyledText) {
             StyledText<?> that = (StyledText<?>) obj;
-            return Objects.equals(this.text, that.text)
-                && Objects.equals(this.style, that.style);
+            return (this.text.isEmpty() && that.text.isEmpty())
+                    || (Objects.equals(this.text, that.text)
+                        && Objects.equals(this.style, that.style));
         } else {
             return false;
         }