Bug: auto-rotation of images not applied without other transformation

[rexxars]

Possible bug

Is this a possible bug in a feature of sharp, unrelated to installation?

• Running npm install sharp completes without error.
• Running node -e "require('sharp')" completes without error.

Are you using the latest version of sharp?

• I am using the latest version of sharp as reported by npm view sharp dist-tags.latest.

What is the output of running npx envinfo --binaries --system --npmPackages=sharp --npmGlobalPackages=sharp?

 System:
    OS: macOS 12.6
    CPU: (10) arm64 Apple M1 Pro
    Memory: 884.92 MB / 32.00 GB
    Shell: 5.8.1 - /bin/zsh
  Binaries:
    Node: 18.7.0 - ~/.nvm/versions/node/v18.7.0/bin/node
    Yarn: 1.22.19 - ~/.yarn/bin/yarn
    npm: 8.15.0 - ~/.nvm/versions/node/v18.7.0/bin/npm
  npmPackages:
    sharp: 0.31.1 => 0.31.1

What are the steps to reproduce?

1. Load an image with an EXIF orientation tag such as 4, 5 or 7
2. Call .rotate() on the pipeline
3. Output the image using toFile()
4. Observe the lack of auto-rotation

What is the expected behaviour?

The images should be automatically rotated based on their exif orientation tag.

(According to the documentation; Rotate the output image by either an explicit angle or auto-orient based on the EXIF Orientation tag.)

All of these images have an exif orientation, but are not automatically oriented. If you add a resize(200, 200) call to the pipeline, it will however rotate them correctly.

Please provide a minimal, standalone code sample, without other dependencies, that demonstrates this problem

Download source images from here: https://timely-scone-c18287.netlify.app/images.zip
(They are also available as https://timely-scone-c18287.netlify.app/input-orientation1.jpg through 8)

const sharp = require('sharp')

async function run() {
  for (let i = 1; i <= 8; i++) {
    sharp(`./input-orientation${i}.jpg`)
      .rotate()
      .png()
      .toFile(`output-orientation${i}.png`)
  }
}

run()

Please provide sample image(s) that help explain this problem

(provided as links in order for GitHub not to alter image and adjust any exif data)

https://timely-scone-c18287.netlify.app/input-orientation4.jpg
https://timely-scone-c18287.netlify.app/input-orientation5.jpg
https://timely-scone-c18287.netlify.app/input-orientation7.jpg

[lovell]

This issue is caused by the same regression behind #3391, but it looks like the fix for that didn't quite go far enough.

Commit 5b0fba4 massively improves the test coverage of auto-rotate logic, including the scenario in this issue, plus of course fixes the problem.

This will be in v0.31.2, thanks for reporting.

[lovell]

v0.31.2 now available.