[Rust Server] Fix #5947 multi tag generate multi method issue. (#5928)

* [Rust Server] Fix issue with multiple tags on an operation generating duplicate methods.

* [Rust Server] Add test case yaml with multiple tags on a single operation.

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RustServerCodegen.java

@@ -1111,6 +1111,27 @@ public class RustServerCodegen extends DefaultCodegen implements CodegenConfig {
         return dataType != null && dataType.equals(typeMapping.get("File").toString());
     }
 
+    /**
+     * Add operation to group
+     *
+     * @param tag          name of the tag
+     * @param resourcePath path of the resource
+     * @param operation    OAS Operation object
+     * @param co           Codegen Operation object
+     * @param operations   map of Codegen operations
+     */
+    @SuppressWarnings("static-method")
+    @Override
+    public void addOperationToGroup(String tag, String resourcePath, Operation operation, CodegenOperation
+            co, Map<String, List<CodegenOperation>> operations) {
+        // only generate operation for the first tag of the tags
+        if (tag != null && co.tags.size() > 1 && !tag.equals(co.tags.get(0).getName())) {
+            LOGGER.info("generated skip additional tag `" + tag + "` with operationId=" + co.operationId);
+            return;
+        }
+        super.addOperationToGroup(tag, resourcePath, operation, co, operations);
+    }
+
     // This is a really terrible hack. We're working around the fact that the
     // base version of `fromRequestBody` checks to see whether the body is a
     // ref. If so, it unwraps the reference and replaces it with its inner

modules/openapi-generator/src/test/resources/3_0/rust-server/openapi-v3.yaml

@@ -362,7 +362,7 @@ paths:
           type: string
         required: true
     get:
-      tags: [Repo]
+      tags: [Repo, Info]
       operationId: GetRepoInfo
       responses:
         "200":

samples/server/petstore/rust-server/output/openapi-v3/api/openapi.yaml

@@ -384,6 +384,7 @@ paths:
           description: OK
       tags:
       - Repo
+      - Info
 components:
   schemas:
     EnumWithStarObject:

samples/server/petstore/rust-server/output/openapi-v3/docs/info_api.md

@@ -0,0 +1,8 @@
+# info_api
+
+All URIs are relative to *http://localhost*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+
+