Also prune away ClearValue updates if possible.

2 files changed, 54 insertions, 0 deletions

diff --git a/document/src/main/java/com/yahoo/document/DocumentUpdate.java b/document/src/main/java/com/yahoo/document/DocumentUpdate.java
index 3374714e3a7..ad93942c1c0 100644
--- a/document/src/main/java/com/yahoo/document/DocumentUpdate.java
+++ b/document/src/main/java/com/yahoo/document/DocumentUpdate.java
@@ -7,6 +7,7 @@ import com.yahoo.document.serialization.DocumentSerializerFactory;
 import com.yahoo.document.serialization.DocumentUpdateReader;
 import com.yahoo.document.serialization.DocumentUpdateWriter;
 import com.yahoo.document.update.AssignValueUpdate;
+import com.yahoo.document.update.ClearValueUpdate;
 import com.yahoo.document.update.FieldUpdate;
 import com.yahoo.document.update.ValueUpdate;
 import com.yahoo.io.GrowableByteBuffer;
@@ -140,6 +141,17 @@ public class DocumentUpdate extends DocumentOperation implements Iterable<FieldP
                     if ((currentValue != null) && currentValue.equals(last.getValue())) {
                         iter.remove();
                     }
+                } else if (last instanceof ClearValueUpdate) {
+                    FieldValue currentValue = doc.getFieldValue(update.getField());
+                    if (currentValue == null) {
+                        iter.remove();
+                    } else {
+                        FieldValue copy = currentValue.clone();
+                        copy.clear();
+                        if (currentValue.equals(copy)) {
+                            iter.remove();
+                        }
+                    }
                 }
             }
         }
diff --git a/document/src/test/java/com/yahoo/document/DocumentUpdateTestCase.java b/document/src/test/java/com/yahoo/document/DocumentUpdateTestCase.java
index 4f3d7d3b820..15319985591 100644
--- a/document/src/test/java/com/yahoo/document/DocumentUpdateTestCase.java
+++ b/document/src/test/java/com/yahoo/document/DocumentUpdateTestCase.java
@@ -709,6 +709,48 @@ public class DocumentUpdateTestCase {
         assertEquals(expected, doc.getFieldValue(field).getWrappedValue());
     }
 
+    @Test
+    public void testThatClearCanBePrunedIfNoneExisting() {
+        Field field = docType.getField("strfoo");
+        Document doc = createDocument();
+        StringFieldValue expected = new StringFieldValue("some value");
+        expected.clear();
+        doc.setFieldValue(field, expected);
+        DocumentUpdate update = new DocumentUpdate(docType, new DocumentId(documentId));
+        update.addFieldUpdate(FieldUpdate.createClearField(field));
+        update.prune(doc);
+        assertEquals(0, update.size());
+        update.applyTo(doc);
+        assertEquals(expected, doc.getFieldValue(field));
+    }
+
+    @Test
+    public void testThatClearCanBePrunedIfEmpty() {
+        Field field = docType.getField("strfoo");
+        String expected = "";
+        Document doc = createDocument();
+        DocumentUpdate update = new DocumentUpdate(docType, new DocumentId(documentId));
+        update.addFieldUpdate(FieldUpdate.createClearField(field));
+        update.prune(doc);
+        assertEquals(0, update.size());
+        update.applyTo(doc);
+        assertNull(doc.getFieldValue(field));
+    }
+
+    @Test
+    public void testThatClearCanBePrunedIfNoneExistingAndLast() {
+        Field field = docType.getField("strfoo");
+        String expected = "";
+        Document doc = createDocument();
+        DocumentUpdate update = new DocumentUpdate(docType, new DocumentId(documentId));
+        update.addFieldUpdate(FieldUpdate.createAssign(field, new StringFieldValue("some value")));
+        update.addFieldUpdate(FieldUpdate.createClearField(field));
+        update.prune(doc);
+        assertEquals(0, update.size());
+        update.applyTo(doc);
+        assertNull(doc.getFieldValue(field));
+    }
+
     private static TensorFieldValue createTensorFieldValue(String tensor) {
         return new TensorFieldValue(Tensor.from(tensor));
     }