From d110ce44933446eff800e6100fc54ccae821c4ad Mon Sep 17 00:00:00 2001
From: teknium1 <127238744+teknium1@users.noreply.github.com>
Date: Wed, 13 May 2026 22:53:09 -0700
Subject: [PATCH] fix(clipboard): only read PNG signature bytes, not entire
 file

Tighten _is_png_file() to read just the 8-byte PNG magic via path.open()
+ read(8), instead of slurping the entire image into memory only to check
the prefix.
---
 hermes_cli/clipboard.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hermes_cli/clipboard.py b/hermes_cli/clipboard.py
index a782c876b26..a6b6da7c06a 100644
--- a/hermes_cli/clipboard.py
+++ b/hermes_cli/clipboard.py
@@ -440,7 +440,8 @@ def _convert_to_png(path: Path) -> bool:
 def _is_png_file(path: Path) -> bool:
     """Return True when *path* starts with the PNG file signature."""
     try:
-        return path.read_bytes().startswith(_PNG_SIGNATURE)
+        with path.open("rb") as f:
+            return f.read(len(_PNG_SIGNATURE)) == _PNG_SIGNATURE
     except OSError:
         return False