Fix for parameter position Error that occurs when binding the same Collection multiple times in R2DBC DatabaseClient

spring-r2dbc/src/main/java/org/springframework/r2dbc/core/NamedParameterUtils.java

@@ -526,17 +526,19 @@ public void bind(BindTarget target, String identifier, Parameter parameter) {
 				return;
 			}
 			if (parameter.getValue() instanceof Collection collection) {
-				Iterator<Object> iterator = collection.iterator();
 				Iterator<BindMarker> markers = bindMarkers.iterator();
-				while (iterator.hasNext()) {
-					Object valueToBind = iterator.next();
-					if (valueToBind instanceof Object[] objects) {
-						for (Object object : objects) {
-							bind(target, markers, object);
+				while(markers.hasNext()){
+					Iterator<Object> iterator = collection.iterator();
+					while (iterator.hasNext()) {
+						Object valueToBind = iterator.next();
+						if (valueToBind instanceof Object[] objects) {
+							for (Object object : objects) {
+								bind(target, markers, object);
+							}
+						}
+						else {
+							bind(target, markers, valueToBind);
 						}
-					}
-					else {
-						bind(target, markers, valueToBind);
 					}
 				}
 			}

spring-r2dbc/src/test/java/org/springframework/r2dbc/core/NamedParameterUtilsTests.java

@@ -16,6 +16,7 @@
 
 package org.springframework.r2dbc.core;
 
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -497,6 +498,66 @@ public void bindNull(int index, Class<?> type) {
 				.containsEntry(0, Parameters.in(String.class));
 	}
 
+	@Test
+	void multipleInParameterReferencesBindsMultiple(){
+		List<String> userIds = List.of("user1", "user2", "user3");
+		String sql = """
+				SELECT * FROM PERSON
+				WHERE name IN (:ids)
+				GROUP BY address
+
+				UNION
+
+				SELECT * FROM PERSON
+				WHERE name NOT IN (:ids)
+				""";
+
+		BindMarkersFactory factory = BindMarkersFactory.anonymous("?");
+
+		PreparedOperation<String> operation = NamedParameterUtils.substituteNamedParameters(
+				sql, factory, new MapBindParameterSource(
+						Collections.singletonMap("ids", Parameters.in(userIds))));
+
+		assertThat(operation.toQuery()).isEqualTo(
+				"""
+				SELECT * FROM PERSON
+				WHERE name IN (?, ?, ?)
+				GROUP BY address
+
+				UNION
+
+				SELECT * FROM PERSON
+				WHERE name NOT IN (?, ?, ?)
+						""");
+		final String[] expectedValues = {"user1", "user2", "user3", "user1", "user2", "user3"};
+		final int[] bindingCount = {0};
+		final boolean[] isBinding = new boolean[6];
+		final String[] bindingValue = new String[6];
+		operation.bindTo(new BindTarget() {
+
+			@Override
+			public void bind(String identifier, Object value) {
+				throw new UnsupportedOperationException();
+			}
+			@Override
+			public void bind(int index, Object value) {
+				bindingCount[0]++;
+				isBinding[index] = true;
+				bindingValue[index] = (String) value;
+			}
+			@Override
+			public void bindNull(String identifier, Class<?> type) {
+				throw new UnsupportedOperationException();
+			}
+			@Override
+			public void bindNull(int index, Class<?> type) {
+				throw new UnsupportedOperationException();
+			}
+		});
+		assertThat(bindingCount[0]).isEqualTo(6);
+		assertThat(isBinding).containsExactly(true, true, true, true, true, true);
+		assertThat(bindingValue).containsExactly(expectedValues);
+	}
 
 	private static String expand(ParsedSql sql) {
 		return NamedParameterUtils.substituteNamedParameters(sql, INDEXED_MARKERS,