Fix StrField.toObject and toExternal to work with docValue IndexableField instances, optimize createFields

solr/CHANGES.txt

@@ -348,6 +348,9 @@ Bug Fixes
 * SOLR-8886: Fix TrieField.toObject(IndexableField) to work for field with docValues
   enabled. (yonik)
 
+* SOLR-8891: Fix StrField.toObject and toExternal to work with docValue IndexableField
+  instances. (yonik)
+
 Optimizations
 ----------------------
 * SOLR-7876: Speed up queries and operations that use many terms when timeAllowed has not been

solr/core/src/java/org/apache/solr/schema/FieldType.java

@@ -353,7 +353,12 @@ public abstract class FieldType extends FieldProperties {
     // currently used in writing XML of the search result (but perhaps
     // a more efficient toXML(IndexableField f, Writer w) should be used
     // in the future.
-    return f.stringValue();
+    String val = f.stringValue();
+    if (val == null) {
+      // docValues will use the binary value
+      val = f.binaryValue().utf8ToString();
+    }
+    return val;
   }
 
   /**

solr/core/src/java/org/apache/solr/schema/StrField.java

@@ -40,21 +40,29 @@ public class StrField extends PrimitiveFieldType {
   }
 
   @Override
-  public List<IndexableField> createFields(SchemaField field, Object value,
-      float boost) {
+  public List<IndexableField> createFields(SchemaField field, Object value, float boost) {
+    IndexableField fval = createField(field, value, boost);
+
     if (field.hasDocValues()) {
-      List<IndexableField> fields = new ArrayList<>();
-      fields.add(createField(field, value, boost));
+      IndexableField docval;
       final BytesRef bytes = new BytesRef(value.toString());
       if (field.multiValued()) {
-        fields.add(new SortedSetDocValuesField(field.getName(), bytes));
+        docval = new SortedSetDocValuesField(field.getName(), bytes);
       } else {
-        fields.add(new SortedDocValuesField(field.getName(), bytes));
+        docval = new SortedDocValuesField(field.getName(), bytes);
       }
-      return fields;
-    } else {
-      return Collections.singletonList(createField(field, value, boost));
+
+      // Only create a list of we have 2 values...
+      if (fval != null) {
+        List<IndexableField> fields = new ArrayList<>(2);
+        fields.add(fval);
+        fields.add(docval);
+        return fields;
+      }
+
+      fval = docval;
     }
+    return Collections.singletonList(fval);
   }
 
   @Override

solr/core/src/test/org/apache/solr/schema/DocValuesTest.java

@@ -116,7 +116,9 @@ public class DocValuesTest extends SolrTestCaseJ4 {
         tstToObj(schema.getField("longdvs"), -11L);
         tstToObj(schema.getField("datedv"), new Date(1000));
         tstToObj(schema.getField("datedvs"), new Date(1000));
-        
+        tstToObj(schema.getField("stringdv"), "foo");
+        tstToObj(schema.getField("stringdvs"), "foo");
+
       } finally {
         searcherRef.decref();
       }