fix(uploads): keep dedupe counter before compound archive suffix (#8042)

Re-uploading a file whose name collides with a compound archive suffix
(e.g. .tar.gz, .tar.bz2) previously inserted the dedupe counter inside
the suffix: a second report.tar.gz became report.tar_1.gz, which broke
file-type detection. Treat the compound suffix as a single extension so
the counter lands before it (report_1.tar.gz), matching single-suffix
behavior (report_1.tar, report_1.txt).

- Add _COMPOUND_SUFFIXES and split stem/suffix as one unit, sorted
  longest-first with a closed, non-overlapping allowlist (.tar.br added).
- Expand tests to all 13 suffixes plus counter-escalation and plain .tar.
- Add a CHANGELOG [Unreleased] Fixed entry.

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

CHANGELOG.md

@@ -58,6 +58,12 @@ This section accumulates work toward the **2.3.0** milestone
   they carry per-call environment variables, including Lark CLI commands.
   Commands within one subagent remain ordered and client cleanup drains them.
 
+- **uploads:** Re-uploading a file whose name collides with a compound archive
+  suffix no longer inserts the dedupe counter inside the suffix. A second
+  `report.tar.gz` is now named `report_1.tar.gz` (matching `report_1.tar` and
+  `report_1.txt`), instead of `report.tar_1.gz`, so the extension stays intact
+  for file-type detection. ([#8042](https://github.com/bytedance/deer-flow/pull/8042))
+
 - **gateway:** Deleting a thread no longer reports success while its
   conversation stays readable. When the checkpoint store failed during
   `DELETE /api/threads/{id}`, the route logged it at DEBUG, removed the

backend/packages/harness/deerflow/uploads/manager.py

@@ -42,6 +42,44 @@ UPLOAD_STAGING_MIN_AGE = timedelta(hours=24)
 
 _MAX_FILENAME_BYTES = 255
 
+# Multi-segment archive suffixes that must be treated as a single extension
+# when deduplicating, so ``report.tar.gz`` becomes ``report_1.tar.gz`` instead
+# of ``report.tar_1.gz``. Sorted longest-first so the longest match wins; the
+# list is deliberately closed (not every compression format is listed), and no
+# entry is a proper suffix of another, so a future addition (e.g. ``.tar.lzo``
+# beside ``.tar.lz``) stays safe regardless of position.
+_COMPOUND_SUFFIXES = (
+    ".tar.lzma",
+    ".tar.bz2",
+    ".tar.zst",
+    ".tar.lz4",
+    ".tar.br",
+    ".tar.gz",
+    ".tar.lz",
+    ".tar.xz",
+    ".tar.z",
+    ".tbz2",
+    ".tzst",
+    ".tgz",
+    ".txz",
+)
+
+
+def _split_stem_suffix(name: str) -> tuple[str, str]:
+    """Split *name* into ``(stem, suffix)``.
+
+    Unlike :meth:`pathlib.Path.stem`/:meth:`pathlib.Path.suffix`, which only
+    strip the final extension, this keeps known compound archive suffixes
+    (``.tar.gz``, ``.tgz``, ...) intact so a deduplication counter lands
+    before the whole archive suffix.
+    """
+    lowered = name.casefold()
+    for compound in _COMPOUND_SUFFIXES:
+        if lowered.endswith(compound):
+            return name[: -len(compound)], name[-len(compound) :]
+    path = Path(name)
+    return path.stem, path.suffix
+
 
 def get_uploads_dir(thread_id: str, *, user_id: str | None = None) -> Path:
     """Return the uploads directory path for a thread (no side effects)."""
@@ -122,7 +160,7 @@ def claim_unique_filename(name: str, seen: set[str]) -> str:
     if name.casefold() not in claimed:
         seen.add(name)
         return name
-    stem, suffix = Path(name).stem, Path(name).suffix
+    stem, suffix = _split_stem_suffix(name)
     counter = 1
     while True:
         tag = f"_{counter}"

backend/tests/test_uploads_manager.py

@@ -200,6 +200,62 @@ class TestDeduplicateFilename:
         seen = {"data.txt"}
         assert claim_unique_filename("data.txt", seen) == "data_1.txt"
 
+    @pytest.mark.parametrize(
+        ("name", "expected"),
+        [
+            ("report.tar.gz", "report_1.tar.gz"),
+            ("report.tar.bz2", "report_1.tar.bz2"),
+            ("report.tar.xz", "report_1.tar.xz"),
+            ("report.tar.zst", "report_1.tar.zst"),
+            ("report.tar.lz", "report_1.tar.lz"),
+            ("report.tar.lz4", "report_1.tar.lz4"),
+            ("report.tar.lzma", "report_1.tar.lzma"),
+            ("report.tar.z", "report_1.tar.z"),
+            ("report.tar.br", "report_1.tar.br"),
+            ("report.tgz", "report_1.tgz"),
+            ("report.tbz2", "report_1.tbz2"),
+            ("report.txz", "report_1.txz"),
+            ("report.tzst", "report_1.tzst"),
+        ],
+    )
+    def test_compound_archive_suffix_keeps_counter_before_suffix(
+        self,
+        name: str,
+        expected: str,
+    ):
+        """The ``_N`` counter lands before the whole archive suffix, not
+        inside it (``report.tar_1.gz`` is wrong)."""
+        seen = {name}
+        assert claim_unique_filename(name, seen) == expected
+        assert expected in seen
+
+    def test_plain_tar_suffix_keeps_original_dedupe_shape(self):
+        """A plain ``.tar`` (single suffix, not in the compound list) still
+        dedupes as ``report_1.tar``."""
+        seen = {"report.tar"}
+        assert claim_unique_filename("report.tar", seen) == "report_1.tar"
+        assert "report_1.tar" in seen
+
+    def test_compound_suffix_counter_escalation(self):
+        """A second collision re-enters the compound split, producing
+        ``report_2.tar.gz`` rather than mangling the suffix."""
+        seen = {"report.tar.gz", "report_1.tar.gz"}
+        assert claim_unique_filename("report.tar.gz", seen) == "report_2.tar.gz"
+        assert "report_2.tar.gz" in seen
+
+    def test_compound_suffix_collision_is_case_insensitive(self):
+        seen = {"Report.Tar.Gz"}
+        assert claim_unique_filename("report.tar.gz", seen) == "report_1.tar.gz"
+
+    def test_compound_suffix_max_length_stays_within_filename_limit(self):
+        # 250-byte stem + 7-byte ".tar.gz" = 257 bytes; dedupe must truncate
+        # the stem so the counter + suffix still fit in 255 bytes.
+        name = "a" * 250 + ".tar.gz"
+        seen = {name}
+        deduped = claim_unique_filename(name, seen)
+        assert deduped.endswith(".tar.gz")
+        assert len(deduped.encode("utf-8")) <= 255
+
 
 # ---------------------------------------------------------------------------
 # validate_path_traversal