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Merged
eilandert merged 1 commit into from
Jul 15, 2026
Merged

test: fix false-positive corruption in reload-under-load harness #81

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14 changes: 10 additions & 4 deletions tools/test_reload_under_load.py
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Original file line number Diff line number Diff line change
Expand Up @@ -128,7 +128,7 @@ def wait_port(port: int, timeout: float = 10.0) -> None:
raise RuntimeError(f"nothing listening on 127.0.0.1:{port}")


def one(port: int, rid: int, zstd_bin: str) -> None:
def one(port: int, rid: int, zstd_bin: str, dict_path: pathlib.Path) -> None:
req = urllib.request.Request(
f"http://127.0.0.1:{port}/r/{rid}",
headers={"Accept-Encoding": "zstd",
Expand All @@ -141,8 +141,14 @@ def one(port: int, rid: int, zstd_bin: str) -> None:
blob = resp.read()
if blob[:4] != b"\x28\xb5\x2f\xfd":
raise RuntimeError(f"rid={rid}: no zstd magic")
r = subprocess.run([zstd_bin, "-dq", "-c"], input=blob,
capture_output=True)
# nginx.conf below sets zstd_dict_file, so every response is compressed
# against that dictionary (ZSTD_CCtx_refCDict in the filter module) --
# the decoder needs the same dictionary via -D, or libzstd correctly
# rejects the frame as "Data corruption detected" even though nothing is
# actually corrupt. Omitting -D here previously made this test fail on
# every run regardless of reload timing (any response, any size).
r = subprocess.run([zstd_bin, "-dq", "-c", "-D", str(dict_path)],
input=blob, capture_output=True)
Comment on lines +144 to +151

@coderabbitai coderabbitai Bot Jul 15, 2026

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📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick win

🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
set -eu
ruff check --select PLW1510 tools/test_reload_under_load.py

Repository: myguard-labs/nginx-zstd-module

Length of output: 861

Add check=False to this subprocess.run call. The non-zero decoder exit is handled manually, and the explicit flag silences Ruff PLW1510.

🧰 Tools
🪛 ast-grep (0.44.1)

[error] 149-150: Command coming from incoming request
Context: subprocess.run([zstd_bin, "-dq", "-c", "-D", str(dict_path)],
input=blob, capture_output=True)
Note: [CWE-78] Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection').

(subprocess-from-request)

🪛 Ruff (0.15.21)

[error] 150-150: subprocess call: check for execution of untrusted input

(S603)

[warning] 150-150: subprocess.run without explicit check argument

Add explicit check=False

(PLW1510)

🤖 Prompt for AI Agents 
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@tools/test_reload_under_load.py` around lines 144 - 151, Update the
subprocess.run invocation that decodes the response blob to explicitly pass
check=False, preserving the existing manual handling of non-zero decoder exits
and satisfying Ruff PLW1510.

Source: Linters/SAST tools

if r.returncode != 0:
raise RuntimeError(f"rid={rid}: zstd -d failed: "
+ r.stderr.decode("utf-8", "replace"))
Expand Down Expand Up @@ -235,7 +241,7 @@ def worker():
rid = counter["n"]
counter["n"] += 1
try:
one(args.port, rid, args.zstd_bin)
one(args.port, rid, args.zstd_bin, dict_path)
except Exception as e: # noqa: BLE001
failures.append(str(e))

Expand Down
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