Custom site identity Crop Image function does not work for images smaller than 512px

[obermeister8080]

Site Identity image.
After the image source is selected, crop image popup window arises.
Then the image is shown in a crop frame, but crop function does not work as crop frame does not react to mouse.

Wordpress 4.9.1
Firefox 57.0.4 64
Internet Explorer 11.192.16299.0

[obermeister8080]

Firefox view

[obermeister8080]

IE View

[joyously]

I recently saw this same thing on a header image crop, but I was running WP 4.7.8. In my case, I speculated that the values given by the theme for width and height were not right.
I just tried both again with that same theme (fixed numbers for header image), and both worked (on 4.7.8).

On 4.9.1, the mouse is not responding to clicks on the right, bottom, or left edges or corners. But I can grab the top of the crop box and pull down. I can also drag the box around once it is small enough. And once the box is moved, I can grab all the edges as normal. (test done on SeaMonkey browser)

[subrataemfluence]

Hi @obermeister8080,

I tried to reproduce the issue and got the following observation.

For some images the crop handles worked just fine but for some others, the handle did not respond at all.

I tested in both both Firefox [57.0.4 (64-bit)] and Chrome [Version 63.0.3239.132 (Official Build) (64-bit)] on Ubuntu Linux and the behaviour was similar.

What I have seen is if the image dimension is less than 512 x 512 sq. px. (which is the minimum required dimension as per on-screen message), the handles do not response.

However, when I tried an image with dimension width:height :: 712px:417px, the crop handle does not work. The reason is because the height is 417px, which is already less than 512px.

But, the interesting thing is this image does not satisfy the on-screen instruction i.e.
"Site Icons should be square and AT LEAST 512×512 PIXELS.".

Since the crop handles only allow square cropping and we cannot drag side handles (only corner handles are accessible), images which cannot satisfy 512x512 sq. px. size after cropping, the handles will probably not work.

However, looking at the scenario, I should not be able to use 712px x 417px image or the on-screen instruction needs to be modified!

[celloexpressions]

Cropping is not "allowed" if either image is less than 512px, but the image will be cropped to square in this scenario. It sounds like the help text could be updated and/or additional checks put in place to require large enough base images to be uploaded. There could also be improvements to allow adjusting the crop extents (but not overall size) for smaller non-square images.