Fix uri format with duplicate fields

Signed-off-by: whl <[email protected]>

Author: whlit

Diff for: spring-web/src/main/java/org/springframework/web/util/HierarchicalUriComponents.java

@@ -443,7 +443,7 @@ private MultiValueMap<String, String> expandQueryParams(UriTemplateVariables var
 		UriTemplateVariables queryVariables = new QueryUriTemplateVariables(variables);
 		this.queryParams.forEach((key, values) -> {
 			String name = expandUriComponent(key, queryVariables, this.variableEncoder);
-			List<String> expandedValues = new ArrayList<>(values.size());
+			List<String> expandedValues = result.getOrDefault(name, new ArrayList<>(values.size()));
 			for (String value : values) {
 				expandedValues.add(expandUriComponent(value, queryVariables, this.variableEncoder));
 			}