Merge branch 'ksi-fish-title' of https://github.com/page-down/kitty

shell-integration/fish/vendor_conf.d/kitty-shell-integration.fish

@@ -55,6 +55,11 @@ function _ksi_main
     end
 
     if not contains "no-title" $_ksi
+        function _ksi_function_is_not_overridden -d "Check if the specified function is not overridden"
+            string match -q -- "$__fish_data_dir/functions/*" (functions --details $argv[1])
+        end
+
+        if _ksi_function_is_not_overridden fish_title
             function fish_title
                 if set -q argv[1]
                     echo $argv[1]
@@ -64,6 +69,9 @@ function _ksi_main
             end
         end
 
+        functions --erase _ksi_function_is_not_overridden
+    end
+
     if not contains "no-prompt-mark" $_ksi
         set --global _ksi_prompt_state "first-run"
 
@@ -131,6 +139,8 @@ function _ksi_main
         # with prompt marking kitty clears the current prompt on resize so we need
         # fish to redraw it
         set --global fish_handle_reflow 1
+
+        functions --erase _ksi_function_is_not_empty
     end
     functions --erase _ksi_main _ksi_schedule
 end