8251946: ObservableList.setAll does not conform to specification

Reviewed-by: arapte, kcr

Author: TheMrMilchmann

modules/javafx.base/src/main/java/com/sun/javafx/collections/VetoableListDecorator.java

@@ -113,8 +113,7 @@ public boolean setAll(Collection<? extends E> col) {
         onProposedChange(Collections.unmodifiableList(new ArrayList(col)), 0, size());
         try {
             modCount++;
-            list.setAll(col);
-            return true;
+            return list.setAll(col);
         } catch(Exception e) {
             modCount--;
             throw e;

modules/javafx.base/src/main/java/javafx/collections/ModifiableObservableListBase.java

@@ -88,14 +88,15 @@ public ModifiableObservableListBase() {
 
     @Override
     public boolean setAll(Collection<? extends E> col) {
+        if (isEmpty() && col.isEmpty()) return false;
         beginChange();
         try {
             clear();
             addAll(col);
+            return true;
         } finally {
             endChange();
         }
-        return true;
     }
 
     @Override

modules/javafx.base/src/test/java/test/javafx/collections/ObservableListTest.java

@@ -255,6 +255,29 @@ public void testSet() {
         assertEquals("two", r);
     }
 
+    @Test
+    public void testSetAll() {
+        useListData("one", "two", "three");
+        boolean r = list.setAll("one");
+        assertTrue(r);
+
+        r = list.setAll("one", "four", "five");
+        assertTrue(r);
+
+        r = list.setAll();
+        assertTrue(r);
+
+        r = list.setAll("one");
+        assertTrue(r);
+    }
+
+    @Test
+    public void testSetAllNoUpdate() {
+        useListData();
+        boolean r = list.setAll();
+        assertFalse(r);
+    }
+
     @Test
     public void testObserverCanRemoveObservers() {
         final ListChangeListener<String> listObserver = change -> {