[fix-3843][api] When update workflow definition,if name already exists, the prompt is not friendly

dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/service/ProcessDefinitionService.java

@@ -382,24 +382,25 @@ public class ProcessDefinitionService extends BaseDAGService {
             return checkProcessJson;
         }
         ProcessDefinition processDefine = processService.findProcessDefineById(id);
-        if (!name.equals(processDefine.getName())) {
-            ProcessDefinition definition = processDefineMapper.verifyByDefineName(project.getId(), name);
-            if (definition != null) {
-                putMsg(result, Status.VERIFY_PROCESS_DEFINITION_NAME_UNIQUE_ERROR, name);
-                return result;
-            }
-        }
-
+        // check process definition exists
         if (processDefine == null) {
-            // check process definition exists
             putMsg(result, Status.PROCESS_DEFINE_NOT_EXIST, id);
             return result;
-        } else if (processDefine.getReleaseState() == ReleaseState.ONLINE) {
+        }
+
+        if (processDefine.getReleaseState() == ReleaseState.ONLINE) {
             // online can not permit edit
             putMsg(result, Status.PROCESS_DEFINE_NOT_ALLOWED_EDIT, processDefine.getName());
             return result;
-        } else {
-            putMsg(result, Status.SUCCESS);
+        }
+
+        if (!name.equals(processDefine.getName())) {
+            // check whether the new process define name exist
+            ProcessDefinition definition = processDefineMapper.verifyByDefineName(project.getId(), name);
+            if (definition != null) {
+                putMsg(result, Status.VERIFY_PROCESS_DEFINITION_NAME_UNIQUE_ERROR, name);
+                return result;
+            }
         }
 
         Date now = new Date();