don't override default if output_dir is blank

modules/img2img.py

@@ -105,12 +105,13 @@ def process_batch(p, input_dir, output_dir, inpaint_mask_dir, args, to_scale=Fal
 
         proc = modules.scripts.scripts_img2img.run(p, *args)
         if proc is None:
-            p.outpath_samples = output_dir
-            p.override_settings['save_to_dirs'] = False
-            if p.n_iter > 1 or p.batch_size > 1:
-                p.override_settings['samples_filename_pattern'] = f'{image_path.stem}-[generation_number]'
-            else:
-                p.override_settings['samples_filename_pattern'] = f'{image_path.stem}'
+            if output_dir:
+                p.outpath_samples = output_dir
+                p.override_settings['save_to_dirs'] = False
+                if p.n_iter > 1 or p.batch_size > 1:
+                    p.override_settings['samples_filename_pattern'] = f'{image_path.stem}-[generation_number]'
+                else:
+                    p.override_settings['samples_filename_pattern'] = f'{image_path.stem}'
             process_images(p)