From d74bfdee4317abbb12af08262b1d3e2fbeb4fb94 Mon Sep 17 00:00:00 2001
From: anon <38473290+tetsugakusha256@users.noreply.github.com>
Date: Fri, 7 Aug 2026 18:28:37 +0900
Subject: [PATCH] fix: don't require FFD9 as literal last bytes for JPEG
 detection
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Files with data appended after the JPEG EOI marker (Google/Samsung
Motion Photos, etc.) were being rejected by detect_format/is_image
since has_jpeg_end_signature required FFD9 to be the file's final two
bytes. These are valid, fully renderable JPEGs — ImageMagick decodes
them fine, it just stops at EOI and ignores trailing data.
---
 lua/image/utils/magic.lua | 19 ++-----------------
 1 file changed, 2 insertions(+), 17 deletions(-)

diff --git a/lua/image/utils/magic.lua b/lua/image/utils/magic.lua
index 077102e..b53ea10 100644
--- a/lua/image/utils/magic.lua
+++ b/lua/image/utils/magic.lua
@@ -24,15 +24,6 @@ local function read_file_header(file, num_bytes)
   return content and { content:byte(1, #content) } or nil
 end
 
-local function has_jpeg_end_signature(file)
-  if not file then return false end
-  local size = file:seek("end")
-  if size < 2 then return false end
-  file:seek("set", size - 2)
-  local end_signature = file:read(2)
-  return end_signature == "\xFF\xD9", nil
-end
-
 local function check_signature_match(header, format, signature)
   local bytes = { signature:byte(1, #signature) }
   local match = true
@@ -70,14 +61,8 @@ M.detect_format = function(path)
 
   for format, signature in pairs(image_signatures) do
     if check_signature_match(header, format, signature) then
-      if format == "jpeg" then
-        local is_jpeg = has_jpeg_end_signature(file)
-        file:close()
-        return is_jpeg and format or nil
-      else
-        file:close()
-        return format
-      end
+      file:close()
+      return format
     end
   end