Fix read_sid for empty buffers (#65)

fox-it · Jan 14, 2025 · 166f63e · 166f63e
1 parent 2a9439e
commit 166f63e
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Showing 2 changed files with 15 additions and 1 deletion.
diff --git a/dissect/util/sid.py b/dissect/util/sid.py
@@ -28,7 +28,9 @@ def read_sid(fh: BinaryIO | bytes, endian: str = "<", swap_last: bool = False) -
     if isinstance(fh, bytes):
         fh = io.BytesIO(fh)
 
-    buf = fh.read(8)
+    if len(buf := fh.read(8)) != 8:
+        return ""
+
     revision = buf[0]
     sub_authority_count = buf[1]
     authority = int.from_bytes(buf[2:], "big")

diff --git a/tests/test_sid.py b/tests/test_sid.py
@@ -15,9 +15,15 @@ def id_fn(val: bytes | str) -> str:
     if isinstance(val, str):
         return val
 
+    if val == b"":
+        return "empty-value"
+
     if isinstance(val, bytes):
         return val.hex()
 
+    if val is None:
+        return "None"
+
     return ""
 
 
@@ -66,6 +72,12 @@ def id_fn(val: bytes | str) -> str:
             ">",
             True,
         ),
+        (
+            b"",
+            "",
+            "<",
+            False,
+        ),
     ],
     ids=id_fn,
 )