Last-frame pictures go to ComfyUI's temp folder, not the media bin

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Tw9fjYBYFyV8YG5YDfYPRb

core/media.py

@@ -117,7 +117,7 @@ def listing() -> list[dict]:
     if fresh:
         with _LOCK:
             _save_index(items)
-    out = [it for it in items if (config.MEDIA_DIR / it.get("filename", "")).is_file()]
+    out = [it for it in items if not it.get("scratch") and (config.MEDIA_DIR / it.get("filename", "")).is_file()]      # scratch files are not the user's: never listed
     out.sort(key=lambda i: i.get("added", 0), reverse=True)
     return out
 
@@ -166,6 +166,28 @@ def save_upload(orig_name: str, data: bytes, limit=...) -> dict:
     return entry
 
 
+def save_scratch(orig_name: str, data: bytes, folder) -> dict:
+    """A picture the app made for one run (a carried last frame): written into `folder` (ComfyUI's temp folder), answerable by id
+    like any media but never listed in the bin. It goes when the folder is cleared; entries whose file is gone are dropped here."""
+    if not data:
+        raise ValueError("that file is empty")
+    ext = Path(orig_name or "").suffix.lower()
+    if ext not in _IMAGE_EXT:
+        raise ValueError(f"{ext or 'that file type'} is not a picture")
+    mid = uuid.uuid4().hex[:12]
+    target = Path(folder) / (mid + ext)
+    target.parent.mkdir(parents=True, exist_ok=True)
+    target.write_bytes(data)
+    # `filename` is the absolute path: MEDIA_DIR / <absolute> is that path, so path_for, delete and the thumbnails need no second case.
+    entry = {"id": mid, "name": (Path(orig_name or "").name or target.name)[:MAX_NAME], "filename": str(target), "kind": "image",
+             "size": len(data), "added": time.time(), "scratch": True}
+    with _LOCK:
+        items = [it for it in _load_index() if not (it.get("scratch") and not Path(it.get("filename", "")).is_file())]
+        items.append(entry)
+        _save_index(items)
+    return entry
+
+
 def path_for(mid: str) -> Path | None:
     it = get(mid)
     if not it:

modules/output/render/serving.py

@@ -256,7 +256,7 @@ def last_frame(project, scene_id: str, render: dict | None = None, window: dict
     try:
         brightness, peak = files.last_frame(src, out, clip["in"], clip["dur"], clip["fps"], first, at_fraction)
         with open(out, "rb") as fh:
-            entry = media.save_upload(f"last_frame_{projects.safe_part(scene_id)[:12]}.png", fh.read())
+            entry = media.save_scratch(f"last_frame_{projects.safe_part(scene_id)[:12]}.png", fh.read(), os.path.dirname(out))      # a working file in ComfyUI's temp folder, not an upload in the bin
     finally:
         try:
             os.remove(out)

modules/output/render/tests/test_serving.py

@@ -232,13 +232,14 @@ def _post(port, path, body):
 
 
 @needs_ffmpeg
-def test_last_frame_route_saves_a_picture_to_the_bin_once_and_flags_a_fade_to_black(comfy, server):
+def test_last_frame_route_saves_a_picture_to_the_temp_folder_once_and_flags_a_fade_to_black(comfy, server):
     from core import media
     moov_at_end(comfy.output / "a.mp4", 4.0)
     proj = _project(comfy, frames=50, frames_mode="timeline")
     serving._frames.clear()
     status, a = _post(server, f"{BASE}/projects/{proj.id}/last-frame", {"scene_id": "s1"})
     assert status == 200 and a["dark"] is False and media.path_for(a["media_id"])
+    assert media.path_for(a["media_id"]).parent == comfy.temp and a["media_id"] not in [m["id"] for m in media.listing()]      # a working file in temp, never in the user's bin
     assert _post(server, f"{BASE}/projects/{proj.id}/last-frame", {"scene_id": "s1"})[1]["media_id"] == a["media_id"]     # same window: same file
     subprocess.run(["ffmpeg", "-y", "-f", "lavfi", "-i", "color=c=black:s=160x120:d=2:r=25", "-c:v", "libx264", "-pix_fmt", "yuv420p", str(comfy.output / "black.mp4")], check=True, capture_output=True)
     dark = _project(comfy, frames=50, frames_mode="timeline")