Crash while saving images when a "badpictures" folder is created in subdirectory (using Save Images No Display)

[Martyprod]

Hi — I ran into a crash in the node while doing a long batch/tiled upscale run and wanted to report what happened so you can reproduce it.

What happened
While ComfyUI was saving images, I opened the output folder to look through the results and created a subfolder named "badpictures" to move some images I didn't like. As soon as I created that folder (the node was still running and saving), the node crashed and the whole run stopped. The last file it had successfully saved was named like:
334db9cd_251101234108_00001.png

It looks like the node tries to read every entry in the output folder and expects the filenames to have a certain format. When a directory (or any name that doesn't match the expected filename format) appears in that folder while the node is scanning it, the node fails and raises an exception, which kills the run.

How to reproduce

Start a long-running save job that writes images repeatedly into an output folder (filenames like hash_timestamp_counter.png).
While the job is still running and saving files, open that same output folder and create a subfolder named "badpictures" (or any folder/name without the expected separators).
The node will try to parse that new entry and the process will crash (the run stops).

Info I can share
Last successful saved file: 334db9cd_251101234108_00001.png
Crash happens immediately after creating the "badpictures" folder while the node is saving.