restrict plugin file name (#6479)

crates/nu-parser/src/parse_keywords.rs

@@ -3197,13 +3197,28 @@ pub fn parse_register(
         nu_engine::env::env_to_strings(working_set.permanent_state, &stack).unwrap_or_default();
     let error = match signature {
         Some(signature) => arguments.and_then(|(path, encoding)| {
+            // restrict plugin file name starts with `nu_plugin_`
+            let f_name = path
+                .file_name()
+                .map(|s| s.to_string_lossy().starts_with("nu_plugin_"));
+
+            if let Some(true) = f_name {
                 signature.map(|signature| {
                     let plugin_decl = PluginDeclaration::new(path, signature, encoding, shell);
                     working_set.add_decl(Box::new(plugin_decl));
                     working_set.mark_plugins_file_dirty();
                 })
+            } else {
+                Ok(())
+            }
         }),
         None => arguments.and_then(|(path, encoding)| {
+            // restrict plugin file name starts with `nu_plugin_`
+            let f_name = path
+                .file_name()
+                .map(|s| s.to_string_lossy().starts_with("nu_plugin_"));
+
+            if let Some(true) = f_name {
                 get_signature(path.as_path(), &encoding, &shell, &current_envs)
                     .map_err(|err| {
                         ParseError::LabeledError(
@@ -3228,6 +3243,9 @@ pub fn parse_register(
 
                         working_set.mark_plugins_file_dirty();
                     })
+            } else {
+                Ok(())
+            }
         }),
     }
     .err();