Retain filterMany expression when select fetchGroup applied after filterMany

ebean-core/src/main/java/io/ebeaninternal/server/query/DFetchGroup.java

@@ -15,8 +15,8 @@ final class DFetchGroup<T> implements SpiFetchGroup<T> {
   }
 
   @Override
-  public OrmQueryDetail detail() {
-    return detail.copy();
+  public OrmQueryDetail detail(OrmQueryDetail existing) {
+    return detail.copy(existing);
   }
 
   @Override

ebean-core/src/main/java/io/ebeaninternal/server/query/DefaultFetchGroupQuery.java

@@ -52,7 +52,7 @@ public Query<T> select(String columns) {
   @SuppressWarnings("rawtypes")
   @Override
   public Query<T> select(FetchGroup fetchGroup) {
-    this.detail = ((SpiFetchGroup) fetchGroup).detail();
+    this.detail = ((SpiFetchGroup) fetchGroup).detail(detail);
     return this;
   }
 

ebean-core/src/main/java/io/ebeaninternal/server/querydefn/DefaultOrmQuery.java

@@ -769,7 +769,7 @@ public SpiQuery<T> copy(SpiEbeanServer server) {
     copy.useQueryCache = useQueryCache;
     copy.unmodifiable = unmodifiable;
     if (detail != null) {
-      copy.detail = detail.copy();
+      copy.detail = detail.copy(null);
     }
     copy.temporalMode = temporalMode;
     copy.firstRow = firstRow;
@@ -1387,7 +1387,7 @@ public final Query<T> select(String columns) {
   @Override
   public final Query<T> select(FetchGroup<T> fetchGroup) {
     if (fetchGroup != null) {
-      this.detail = ((SpiFetchGroup<T>) fetchGroup).detail();
+      this.detail = ((SpiFetchGroup<T>) fetchGroup).detail(detail);
     }
     return this;
   }

ebean-core/src/main/java/io/ebeaninternal/server/querydefn/OrmQueryDetail.java

@@ -39,12 +39,21 @@ public final class OrmQueryDetail implements Serializable {
   /**
    * Return a deep copy of the OrmQueryDetail.
    */
-  public OrmQueryDetail copy() {
+  public OrmQueryDetail copy(OrmQueryDetail existing) {
     OrmQueryDetail copy = new OrmQueryDetail();
     copy.baseProps = baseProps.copy();
     for (Map.Entry<String, OrmQueryProperties> entry : fetchPaths.entrySet()) {
       copy.fetchPaths.put(entry.getKey(), entry.getValue().copy());
     }
+    if (existing != null) {
+      // transfer any existing filterMany expressions
+      for (Map.Entry<String, OrmQueryProperties> entry : existing.fetchPaths.entrySet()) {
+        var filterMany = entry.getValue().getFilterMany();
+        if (filterMany != null) {
+          copy.getChunk(entry.getKey(), true).setFilterMany(filterMany);
+        }
+      }
+    }
     return copy;
   }
 

ebean-core/src/main/java/io/ebeaninternal/server/querydefn/SpiFetchGroup.java

@@ -10,7 +10,7 @@ public interface SpiFetchGroup<T> extends FetchGroup<T> {
   /**
    * Return the detail to use for query execution.
    */
-  OrmQueryDetail detail();
+  OrmQueryDetail detail(OrmQueryDetail existing);
 
   /**
    * Return the underlying detail for copy purposes.

ebean-querybean/src/test/java/org/querytest/QCustomerTest.java

@@ -13,6 +13,7 @@
 import org.example.domain.query.QContact;
 import org.example.domain.query.QCustomer;
 import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
 import javax.sql.DataSource;
@@ -391,6 +392,23 @@ void filterManyOr() {
     assertThat(q.getGeneratedSql()).contains(" from be_customer t0 left join be_contact t1 on t1.customer_id = t0.id where (t1.id is null or ((t1.first_name like ? escape'|' or t1.last_name like ? escape'|'))) order by t0.id");
   }
 
+  @Test
+  @DisplayName("Retain filterMany expression when select fetchGroup applied after filterMany")
+  void filterManyBeforeSelectFetchGroup_expect_filterManyExpressionRetained() {
+    var fetchGroup = QCustomer.forFetchGroup()
+      .select(name)
+      .contacts.fetch(QContact.Alias.email)
+      .buildFetchGroup();
+
+    var q = new QCustomer()
+      .contacts.filterMany(c -> c.firstName.startsWith("R"))
+      .select(fetchGroup)
+      .query();
+
+    q.findList();
+    assertThat(q.getGeneratedSql()).contains(" t0.id, t0.name, t1.id, t1.email from be_customer t0 left join be_contact t1 on t1.customer_id = t0.id where (t1.id is null or (t1.first_name like ? escape'|')) order by t0.id");
+  }
+
   @Test
   public void testIdIn() {