描述

Expected Behavior

The copied bmp file should be exactly the same as the original one.

Current Behavior

For some reason for this bmp file content gets moved/shifted. It does not happen for all the bmp files.

Failure Information (for bugs)

Steps to Reproduce

I've created minial reproducible repo:

git git@github.com:elderapo/jimp-bmp-bug.git
cd ./jimp-bmp-bug
yarn
yarn start

Screenshots

Context

Jimp Version: ^0.8.4
Operating System: Ubuntu 14.04
Node version: v11.10.0, v12.10.0

Failure Logs

The loading system for bmp files seems to be broken. Exact same thing happens when reading bmp file from disk, buffer. Even when file is saved to a different format it still gets shifted.

貢獻者指南

技術棧: javascriptnodejs
領域: backend
議題類型: bug
難度: 3
預計時間: 1-3 hours
活動狀態: stale
清晰度: mostly clear
前置要求: basic JavaScriptimage format basics
新手友善度: 40
研究方向: Reproduce the bug using the provided minimal reproducible repo. Examine Jimp's BMP decoder, likely in packages/plugin bmp or similar. Compare the original BMP file's pixel data with the output to identify the shift. Check if the issue is due to incorrect handling of BMP padding or color table. Test with different BMP files to confirm affected cases.