From c53b010dd5f4da69b1e42f94d2896afffb1e287a Mon Sep 17 00:00:00 2001
From: Codex <codex@openai.com>
Date: Wed, 29 Jul 2026 00:27:38 -0400
Subject: [PATCH] perf: short-circuit empty hex strings

---
 hexbytes/_utils.py          | 3 +++
 tests/core/test_hexbytes.py | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/hexbytes/_utils.py b/hexbytes/_utils.py
index bc99e14..48bc998 100644
--- a/hexbytes/_utils.py
+++ b/hexbytes/_utils.py
@@ -35,6 +35,9 @@ def hexstr_to_bytes(hexstr: str) -> bytes:
     else:
         non_prefixed_hex = hexstr
 
+    if not non_prefixed_hex:
+        return b""
+
     # if the hex string is odd-length, then left-pad it to an even length
     if len(hexstr) % 2:
         padded_hex = "0" + non_prefixed_hex
diff --git a/tests/core/test_hexbytes.py b/tests/core/test_hexbytes.py
index 36cf1f6..eb435bf 100644
--- a/tests/core/test_hexbytes.py
+++ b/tests/core/test_hexbytes.py
@@ -91,6 +91,11 @@ def test_hex_inputs(hex_input):
     assert_equal(wrapped, expected)
 
 
+@pytest.mark.parametrize("hex_input", ("", "0x", "0X"))
+def test_empty_hex_inputs(hex_input):
+    assert_equal(HexBytes(hex_input), b"")
+
+
 def test_pretty_output():
     hb = HexBytes(b"\x0f\x1a")
     assert repr(hb) == "HexBytes('0x0f1a')"