fix missing logic after rebase

Signed-off-by: Suresh Kumar Moharajan <suresh.kumar.m@ibm.com>

Author: Suresh Kumar Moharajan

mcpgateway/services/resource_service.py

@@ -2961,28 +2961,21 @@ async def update_resource(
                     logger.info(f"Auto-detected MIME type for resource {resource_id}: {detected_mime_type}")
                     resource.mime_type = detected_mime_type
                 else:
-                    resource.mime_type = resource_update.mime_type
-            if resource_update.mime_type is not None or resource_update.uri is not None:
-                # Prefer URL-detected MIME type over user-provided to ensure accuracy
-                uri_for_detection = resource_update.uri if resource_update.uri is not None else resource.uri
-                url_detected_mime = self._detect_mime_type_from_uri(uri_for_detection)
+                    # Non-empty MIME type: prefer URL-detected over user-provided for security
+                    uri_for_detection = resource_update.uri if resource_update.uri is not None else resource.uri
+                    url_detected_mime = self._detect_mime_type_from_uri(uri_for_detection)
 
-                if url_detected_mime:
-                    # URL detection successful - use it
-                    if resource_update.mime_type and resource_update.mime_type != url_detected_mime:
+                    if url_detected_mime and url_detected_mime != resource_update.mime_type:
                         logger.info(f"Using URL-detected MIME type '{url_detected_mime}' instead of user-provided '{resource_update.mime_type}' for resource {resource_id}")
-                    resource.mime_type = url_detected_mime
-                elif resource_update.mime_type is not None:
-                    # No URL detection, handle user-provided value
-                    if not resource_update.mime_type:
-                        # Empty string - fallback to content-based detection
-                        content_for_detection = resource_update.content if resource_update.content is not None else (resource.text_content or resource.binary_content)
-                        detected_mime_type = self._detect_mime_type(uri_for_detection, content_for_detection)
-                        logger.info(f"Fallback MIME type detection for resource {resource_id}: {detected_mime_type}")
-                        resource.mime_type = detected_mime_type
+                        resource.mime_type = url_detected_mime
                     else:
-                        # Use user-provided MIME type
+                        # Use user-provided MIME type if URL detection fails or matches
                         resource.mime_type = resource_update.mime_type
+            elif resource_update.uri is not None:
+                # URI changed but no MIME type provided - try URL detection
+                url_detected_mime = self._detect_mime_type_from_uri(resource_update.uri)
+                if url_detected_mime:
+                    resource.mime_type = url_detected_mime
             if resource_update.uri_template is not None:
                 resource.uri_template = resource_update.uri_template
             if resource_update.visibility is not None: