Fix Crashing issues (#207)

- Prevents crash if no frames were extracted.
- Don't start upload if it was stopped.

vspreview/plugins/builtins/slowpics_comp/main.py

@@ -512,6 +512,7 @@ def on_end_search(self, uuid: str, forced: bool = False, *, conf: FindFramesWork
             self.stop_upload_button.setVisible(False)
             self.upload_progressbar.setValue(int())
             self.upload_status_label.setText('Stopped!')
+            return
         else:
             self.upload_status_label.setText('Finished!')
 

vspreview/plugins/builtins/slowpics_comp/workers.py

@@ -92,6 +92,9 @@ def run(self, conf: WorkerConfiguration) -> None:
                 path_name = conf.path / folder_name
                 path_name.mkdir(parents=True)
 
+                if not conf.frames[i]:
+                    raise StopIteration("Output missing a frame.")
+
                 curr_filename = (path_name / folder_name).append_to_stem(f'%0{ndigits(max(conf.frames[i]))}d').with_suffix('.png')
 
                 clip = output.prepare_vs_output(