Sharp: .resize() crops image when crop is unnecessary

[suprMax]

I'm having trouble with resize function cropping sides of the image when only resize is needed:

// assume expressjs middleware
const resizeTransform = sharp().resize(/* either numbers or undefined-s from querystring */);
const downloadStream = request(req.query.src);
req.pipe(downloadStream).pipe(resizeTransform).pipe(res);

passing along width=200 produces this image:

However passing 199 or 201 produces expected result:

original:

Seems like some strange bug to me. I was expecting to always get a downscaled image in the original aspect ratio. I couldn't find anything in the documentation regarding controlling the crop. How does one achieves resizing this without cropping, and only having crop when both width and height are present?

I already tried converting to JPEG first, passing both dimensions and playing with .max, .min methods, no luck.

Running node v6.10.2, sharp v0.18.0

[lovell]

Hello, I'm currently investigating a problem with JPEG shrink-on-load that appears to have been introduced in v0.18.0 and I believe this is related. v0.17.3 works as expected.

[suprMax]

@lovell ah thank you, I will try downgrading to v0.17.3 and check can confirm that it works as expected with v0.17.3

[lovell]

Commit 9e39a7f fixes the problem I've been investigating. Are you able to confirm the latest code on the master branch fixes things for you too?

[lovell]

...and commit f42a1ce fixes it properly, adding your test case too, thanks for reporting this.

[lovell]

These fixes are in v0.18.1 now available via npm. Please re-open if you're still having related problems.

[suprMax]

Just checked with v0.18.1 and it works great!